Ajax refresh don't work when logged in

Ajax refresh don't work when logged in

  
I tried to install, for the first time, the community edition version 8.0.0.24 in a Windows server 2012, SQL server 2012 and IIS 8.
I then installed an old application that I had working and I’ve found a very peculiar situation.
When I’m logged off, the application works 100% fine.
When I’m logged in, all works fine except some buttons that trigger ajax refresh. They just do nothing.
Any ideas?
No clue what the root cause can be.
Some question trying to find the extend of the issue:
- Do none of the button with ajax refreshes work or some do and other don't?
- Are the not working buttons all on the same page?

For sure, the fact it works when your logged off is very strange. Have no immediate idea what the link between a ajax refresh and (not) being logged in into your application