Vacuum Robot only goes straight

[SunnyD]

I just "upgraded" my pool robot to a Hayward Aquavac 500. I bought it used. The old one did a good job but I thought I'd get something a little newer.

Anyways, I tried it out yesterday and today and have been experiencing issues. It just goes straight. If it bumps into something, it just stays there until it can climb it. If not, it will just keep spinning its wheels. It doesn't figure it out. Any ideas of what the issue can be? I've cleaned it thoroughly but that did nothing.