Should I move out from mug girlfriends place soon, need advice?

I need advice from people that aren’t my girlfriend since I don’t think she’s telling the truth since she wants me to stay and I think this is kind of illegal. So I moved into my girlfriends place in December but what I didn’t tell you guys was that it wasn’t an official move in, I didn’t contact the landlord or anything, I thought that was strange but she said it was fine and that he’s chill

So I split the rent with my girlfriend, living in a place where the landlord doesn’t even know I’m here and I don’t know why she decided to tell me later on that he’s kind of a racist too (I’m black, she’s Irish for context), so I’ve been living here avoiding him since December and my girlfriend told me to stop being afraid of him and that he’ll probably not care if he sees me

So now, the landlord sent a text into the GroupChat that my girlfriend showed me saying that under no circumstance should someone that’s not a tenant be living in someone’s room. Obviously one of the roommates said something, which is annoying because I’m clean and try not to bother anyone but yeah, my girlfriend tells me to stop worrying but this whole thing just seems dodgy, what should I do? Also the job I got doesn’t start until late February which is bs but I should have checked it first