restore of 2FA after resetting of phone

Assuming your time is correct and you're using the correct QR code image (i.e. when you import it the description should read username@Bitstamp) the 6 digit token should work.

Is it possible you disabled 2FA and re-enabled at a later date?  If so the QR code would have changed, so ensure you're using the latest 2FA QR code.

Try restoring the QR code using Authy.

I replicated your scenario and choose Authy instead of Google Authenticator (the token matched exactly on both devices) on my "new" device.

If that fails you must follow the Bitstamp 2FA reset process @ https://www.bitstamp.net/account/two-factor-auth/reset/

In the future you might consider using Authy, as it backs up all your 2FA accounts and is accessible on your desktop as well as multiple devices.

Should try signing in using backup password for that account that you are login
https://support.google.com/accounts/answer/1187538?hl=en

You're really not supposed to store your QR code.  That code is the actual password.  Keeping that QR code means that someone else can potentially make use of it.  You're supposed to generate a new code when you make changes.  Use the backup password to get in and generate a new code.

Not sure how backup passwords for a Google account relates to a 3rd party site such as Bitstamp.

If you have saved your 16-character long authentication key, you should be able to create a new profile on the GA. Otherwise

If you have not saved your 16-character long authentication key, we will need to disable this security feature on your account.

https://www.bitstamp.net/faq/two-factor-authentication-troubleshooting/

Giovani

Assuming your time is correct and you're using the correct QR code image (i.e. when you import it the description should read username@Bitstamp) the 6 digit token should work.

Probably I still have trouble with time synchronization because I get myusername@Bitstamp

I replicated your scenario and choose Authy instead of Google Authenticator (the token matched exactly on both devices) on my "new" device.

I did use Ligntning QR as alternative to Google authenticatior  and I get the same result. ( 6 character code is the same for GA as it is for Ligntning QR)

I have QR image, what is equal to 16-character long authentication key. Correct?

I have 4 different authenticator app and they are all giving me the same 6 digit code for my account login name +@Bitstamp

So i might have trouble with next:

INVALID AUTHENTICATION CODE With Two-factor authentication, it is very important that the time on our server and your mobile device and the time within your Google Authenticator app are all in sync. Therefore, please try to re-sync Google Authenticator by going to Settings -> Time correction for codes -> Sync now, or if you use iOS please set Settings -> General -> Date & Time -> Set Automatically -> to On, then make sure your mobile device displays the correct time and try again.

Next I do not understand:

time on our server

and are they talking about 3 differnt times ?

it is very important that the time on our server(1) and your mobile device(2)and the time within your Google Authenticator app(3)

The QR image is equal to 16-character long authentication key. The sync is with the phone and device current time which the apps will depend on. Anyway, it is best to send request for help to the bitstamp support. See the advice

https://www.bitstamp.net/article/two-factor-authentication-2fa/

Then, the old QR code is invalid.  The code contains the key.  The key should always generate the same 6 digit code based on the same time slice.  You will need to generate a new QR key code.

I get next on google autenticator:

internal authenticator clock was not adjusted because it appears to already be in sync with google servers

Does it make difference if I am in sync with Google servers or with Bitmap server?

Why my QR is invalid?

I just did reset my phone to fabric settings.

See

With Two-factor authentication, it is very important that the time on our server and your mobile device and the time within your Google Authenticator app are all in sync. Therefore, please try to re-sync Google Authenticator by going to Settings -> Time correction for codes -> Sync now

As suggested better to seek support from bitstamp

When prompted to enter your 6-digit two factor code, simply click the "here" link below the code entry bar and follow the instructions. We will review your request and reply in the shortest time possible

https://www.bitstamp.net/faq/two-factor-authentication-troubleshooting/

Is it posible that each time that I will reset my telephone , I will have to ask help from Bitstamp.

No, you need to save your newly issued 16-digit authentication key in a secure place where only you can access it for recovery.
https://www.bitstamp.net/faq/#how-do-i-enable-two-factor-authentication-on-my-account
You can check out the guide too
https://www.bitstamp.net/s/documents/bitstamp_2_factor_authentication_guide.pdf

But I have also now 16-digit authentication key (equal to QR code) from before I was resetting my phone.  And I can not use it.

What difference will be, if I go through protocol of enabling of new QR, if I will be then at same point , if I reset my phone again?

I repeat again I did save my QR code which has the same purpose as 16-digit authentication key. But after resetting of my phone I can not make it work any more.

I was reading about it and watching many videos  about what must you do if you lose your phone or if your phone becomes dysfunctional in any way. Always the same story:
" If you have your 16-digit authentication key  or QR code.... " and " time on your phone must be in sync with...."

But in my case  6 digit  code generated from GA is not matching ...

I want to have this clear. What I am doing wrong?

Have bitstamp support advice instead?
If you restore in another phone, does it work?
I am asking these as in you try all such sync device and apps time, retry the authentication key as you copied it and I suspect if it is the account that has been locked out after multiple tries.

Have bitstamp support advice instead?

They were also saying ask for new QR.
But they were not saying why I have to ask for new. What I am doing wrong?

If you restore in another phone, does it work?

I have the same problem on the other two phones. And I don't know what is the problem.

I am asking these as in you try all such sync device and apps time, retry the authentication key as you copied it and I suspect if it is the account that has been locked out after multiple tries.

If I did a mistake, then I will do it again next time.

So....

I will write to them again and ask for explanation.

QR Codes are supposed to be used only once.  If something happones to them, you're supposed to generate a new one for security.

It seems that your old QR code got out of sync somehow or your key got reset on bitstamp.  Generate a new code.

I am waiting for them to process my reset request.