Back again. I swep whole testing site, delete database and reinstall everything including wordpress and forum loos OK now.
But on my production site which is running on Divi the problem still exist. So it will be really something on Divi´s end…
Hi Robin, fully understand. Thanks for your reply.
The issue appears on default wordpress theme and the same appears on Divi theme. I already discuss with the support from Divi and they´v replied, that it has something to do with plugin itself.