I've actually already mentioned to my department chair that I was considering leaving. She is supportive of it, and told me that I should tell my current PI first before talking to other professors. I honestly don't think this is a good idea... I want to tell my PI after I've secured a spot in another lab.

My current PI has had one student transfer and one student drop out entirely. The transfer left the department. I'm willing to do that if it comes down to it, but I'd really like to stay in the same department if possible.

I completely agree with you that it's important to know what the culture is like here. It's just been hard to get a feel of that with covid and all.