Outlook 2016 - Office 365 & Public Folders hanging

Hello to all,
I'm a new sysadmin in a company that uses O365 w/ exchange online, just to inform you i'm a medium-skilled guy IT,
They're using a lot the Public folders, and we are having an issue.
On the first launch of outlook, when expanding pubfolders for 1st time, outlook hangs until sync is done - for around 2-3 minutes, and its really annoying for everyone,
I've disabled the add-ins, with no result. Updated to latest version, with no result, run outlook in safe mode with no results, run outlook with /cleanviews with no result!
Any other recommendations would be perfect!
Dear SirAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Vasil Michev (MVP)Commented:
Where are the PFs created, in O365? If so, it's normal to have some delay compared to on-premises solutions. One way to handle this is to make sure you are using Outlook in Cached mode, with the "download PF favorites" option configured, and to add all PFs you access regularly to the Favorites. It will not help a lot when you browse the whole PF tree however, especially when it's larger in size. For this, perhaps try and use OWA instead, the "Public folder picker" dialog there can be used to simply navigate the tree, although accessing the actual content is certainly not as easy in OWA.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Dear SirAuthor Commented:
Hello Michev and thanks for your time to reply,
PFs are in O365, and Outlook is set up already in "cached exchange mode"  
OWA is not even a choice here, as the web-app is not convenient for my users.
In that case, patience is the key? There is no other option for PFs to, lets say download all locally, for faster browsing?

Vasil Michev (MVP)Commented:
That's essentially what the "download PF favorites" options does, caches (some of) the PF locally for faster access.
Dear SirAuthor Commented:
So, it must be the PF general size.
Thank you Vasil :)
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Office

From novice to tech pro — start learning today.