No amount of functional manual black box testing is going to maintain quality in a game with complex systems, it's going to get worse and worse. This approach somewhat works if you have telemetry, here they have nothing but often unreliable bug reports in forum threads. They may have an internal...
I find it a bit suspicious that basic things break so easily from build to build, are there no unit tests, is there no continuous integration pipeline to automatically build the codebase every time there's a change in the code (hint: there most likely isn't, otherwise the build number would be...