Assassin's Creed Origins clobbers rbx in its main module (second of three) TLS callbacks. That is apparent right in the beginning of the TLS callback disassembly when rbx is set to '4' unconditionally without any prior save. That leads to a fault in call_tls_callbacks() which is still in __TRY block and gets handled. However the third TLS callback is not executed and that leads to intermittent hangs later on.
It is rather involved to make a TLS callback test in Wine testsuite as there is no portable way to generate a custom TLS callback. I've made a test program (based on the example here: https://lallouslab.net/2017/05/30/using-cc-tls-callbacks-in-visual-studio-wi...) and compiled it with MSVC. The source code is here: https://gist.github.com/gofman/3287a953bcab3a5c888a8d494461cb8a. The program calls all the callbacks on Windows 10 here.
There is also a similar wrapper already there for i386 on another occasion.
-- v2: ntdll: Preserve rbx register when calling DLL entry point on x64.