system.log flooded with xpcproxy errors during sleep time. How do I diagnose?
Further investigation: wake-up loop was due to a bad USB hub chain which probably makes Catalina go mad (but worked with Mojave). Reconnected 2 hubs and a Thunderbolt dock in a different order and solved it.

Anyway the xpcproxy error is there at every wake-up but at least not in constant loop.