Didn't find anything which will help me to solve the problem.
Server logs are fine, no PHP log file in Folder,
Webserver logs show the urls and at least the GET /osTicket/api/auth/oauth2 code=XXXXXXXX and GET /osticket/ - 80 -
I'm not very familiar with this configurations. Do you have any idea or other suggest that will help me.
As I said, there haven't been any changes from our site