Yes it's terribly buggy. Incorrect answers sometimes depending on release versions and solve gets stuck all the time. I tend to use Xcas/GIAC instead where I can. Also bundled on my calculator (HP Prime).
It's so bad that the university I "loosely associate" with have their own patched version to fix a load of problems with it.
Indeed. The problem is that there is no regression suite clearly. Sometimes things get broken and then have to be fixed again. You end up in situation where you need to tell a person to use a specific version and hope they know how to get it working.
This makes communication, which is a really big part of mathematics, extremely difficult.
It's so bad that the university I "loosely associate" with have their own patched version to fix a load of problems with it.