Monoprice Mini Delta V2 Stuck on connecting

I just switched to Astroprint while having no luck with Octoprint, and it won’t connect. I’ve tried all the baud rates, but with no luck. This is a 2nd printer, so it’s brand new. But, it just refuses to connect. It’s stuck on just “connecting”. I’ve tried many USB cables, but no luck. Any help? I’m using a raspberry pi 400.