itunes-not recognising iphone

Dear experts,

I have the following two iphones
Iphone 6s+ - UK Account
and iphone 5s. - India account.

The itunes on windows 10 laptop does not recognise the iphones. I have gone to my iphones and entered the password and
opted for 'allow' itunes to access my iphone.

I use the relevant itunes accounts when plugging in with itunes.

I have authorised the computer as well (separately for each itunes account)

I have looked at File->Devices and it does not highlight/display any connected devices.

Kindly advice.