Are you in the OMSCS or on-campus program? I'm currently enrolled in CS 6601 (Artificial Intelligence) via OMSCS, and while it's extremely difficult material that requires a lot of personal investment to master, I've found both TAs and other students to be as helpful as one could reasonably expect.
OMSCS. The TAs refuse to answer questions because it could help cheating. They won't review homework because it could help cheating. They've created an environment so full of fear that it's impossible to learn from mistakes. I'm surprised the slack channel is allowed.
I've never had a direct question to a TA go unanswered (and I've asked my fair share of questions). They're not going to just give you the solution to the homework, though. I guess it depends on what kind of questions you're asking?
