I recall the other plausible rrrrrrrrrrrat being that she had started hanging out with the Mean Girls of Cyberlive again. Some supporting evidence for this is a stream when Lumi talked about Yuri hanging out with the wrong(?) people (someone who knows can pull up the clip). There was also some look into her personality and I recall some people saying she'd be prone to submitting to such a clique and being a lackey.
I could see a situation where she buddies up with a mean girl clique, and said clique then starts causing problems for other Phase members (don't ever underestimate the spitefulness and general social destructiveness of a mean girl clique). Fishman could've told her to stop talking to them, and she was off an on with it, until it boiled up to a point. This also lines up with what Lia was talking about at one point, which (if I recall correctly) she was saying felt lied to by someone in her life. So maybe this group was causing her problems, Yuri said she dropped them, but didn't, and maybe Yuri kept giving them info (in casual talk) that they used to make Lia (and others) miserable?
All a supposition, with wild speculation, I know, but I can not stress, never underestimate a mean girl clique.