The log spam, which continues on 24.10 at the rate of one new error logged per second, is from the UPS graph module, and the failure explains why the UPS graphs are all blank for a remote UPS.
/usr/lib/netdata/charts.d/nut_ups.chart.sh doesn’t support a UPS when it is in netclient (slave) mode - it attempts to query for the UPS name using upsc -l which fails as the host is not specifed (it needs to use upsc -l host when in netclient mode, where host is the remote UPS Master)
Hopefully this can be fixed so that a slave UPS can be graphed, or at least the upsc -l spam needs to be stopped - my 24.10 system has only been up for 6 hours and there are already over 30,000 upsc -l errors in /var/log/netdata/error.log.