Could it be related to this useless 20H2 update with more crap added to Windows 10??
I would put my money on that, and possibly Defender or other security changes. But also, JRiver updated their security Certificate (Digital Signature) in MC27.0.39, which Defender didn't like, and complained during updates. It could be that combined with normal Defender functionality is blocking the deletes.
Eric's logs seem to suggest that recordings were not stopped because MC thought they were already stopped. The parameter that was set to indicate various stages of a recording was "stopped". Strange. I will keep an eye on it.
27.0.38 (11/30/2020)5. Changed: Made digital TV code more robust against bad data.27.0.35 (11/20/2020)8. Changed: Error checking is added when loading certain TV settings to avoid crashes.12. Changed: MC will be more responsive at startup when it processes TV recording actions.27.0.31 (11/11/2020)3. Changed: When playing a DMS TV channel with a streaming tuner, time-shifting will observe user configured time-shifting limit, so that disk space usage will not grow indefinitely.6. Changed: Time-shifting buffer file for DMS TV channels are created in user-set TV recording folder, instead of in MC's temporary file folder.27.0.29 (11/02/2020)2. NEW: Time-shifting works on streaming TV tuners (Pause/Resume, Jump/Skip for now. FF/REW will come later).