Yeah, this happens. Check to see if your node is signed into Alby. The connection will log out your node whenever they are doing system updates, or something like that. I've had this happen to me a few times.
Perhaps it is an nostr:nprofile1qqsyv47lazt9h6ycp2fsw270khje5egjgsrdkrupjg27u796g7f5k0spzemhxue69uhk2er9dchxummnw3ezumrpdejz7qgwwaehxw309ahx7uewd3hkctcprdmhxue69uhkummnw3ez6vfwde3x7tnpdenkzmnf9e3k75xqss4 issue at the moment. Anyone else having issues? 
Discussion
Apparently it fixed itself. I can now zap. Cheers