One of the recent updates caused avatars to get randomly perf blocked despite all (but visitor) safety settings set to show avatar and min perf rank set to VeryPoor. This also happens for friends with default avatar visibility.
Safety settings are set to:
Visitors: Voice
New User: Voice, Avatar
User: Voice, Avatar
Known User: Voice, Avatar
Trusted User: Voice, Avatar
Friends: Voice, Avatar
Min Perf Rank: VeryPoor
Max DL Size: No Limit
Limit Dyn Bone: No
When loading into a world and avatars are perf blocked, toggling Voice for Visitors off is enough to trigger a reload of all avatars which causes those avatars to actually load, re-enabling Voice for Visitors reloads the avatars again but leaves the previously perf blocked avatars loaded now.
Demonstration video showing this behavior: https://youtu.be/mH9chzo4imo