Hello,
I noticed that my TB1.1.X mostly does not work on cell phones. I tested it with Galaxy S10+, S8, S20 and Android Tablet. Each device hangs mostly after a few seconds, sometimes however rarely I have seen it work properly. My TB1.1.X was a clean install with Panda theme. Anyway, there are no error logs on the server side. After I contacted the web host, he couldn't find any server problems either.
In my opinion, the web host can't find any problem because I have a second other domain with exactly the same configuration (clean TB1.1.X installation with Panda). At the moment I'm at the end of how to debug the problem further.
Hopefully you have some tips for identifying the root cause.