FCP rendering glitchy frames suddenly and randomly

Been using this workflow for years. Render out master file from FCP drag it into Adobe media encoder to make an mp4 compressed video. I do this multiple times a day almost every day... hundreds of times with no issues. Suddenly starting about 5 days ago, ME starts failing on compression, and states a specific frame that's the cause. When I look at the frame in the master file output, there is some small group of messed up pixels. see attached. Random spots in the frame, usually just a small area. This is happening in about 50% of my outputs, which after years of zero issues, is stunning. I don't know if FCP has always done this and now for some reason ME can't deal with it, or if this has not been a problem for FCP until now, and the renders are the problem. The bad frames don' exist in either the raw footage or the timeline. I export Prores 422 standard. have tried using HQ and turned off "include chapter markers" to no avail. Can anyone help? I'm on a Mac Pro trash can running Monterey and the latest FCP and the latest ME. It happens with all kinds of footage. This is from a C300 and I shoot with a GH6. It also happens with mp4 footage out of Zoom... s it's not a specific camera or video format. Any ideas at all?