@gloomyandy reverting back to 3.5.4 resolves the issue.
@tcamguil thanks for the recommendation on rc1. I installed it when it released and encountered the probe initialization error so I never revisited it for the trigger issue. I hadn't considered running mixed versions and overlooked the solution when I read your post a few days ago. I tested 3.6.0-rc2+4 on the Mini 5+ and 3.6.0-rc1 on the 1LC and that seems to be a winning combination. I made it through 6 consecutive G32 sequences at ~15 probes per leveling without a fault.
I think my issue and one of @tcamguil's are the same. I only get the reported trigger failure if I let it hammer the nozzle into the bed for a second or two (at very reduced stepper currents). I usually hit the e-stop and the probe is always in the triggered state following the reboot.
.