I ran the update to core v6.0.6, FTL v6.1 and Web Interface v6.1 moments ago. Pihole is operating normally except for the Query Log and Tools/Pihole diagnosis.
Query log doesn't show anything, nor does Tail Log files/pihole.log; if I go to /var/log I can see pihole.log and tail it successfully from terminal.
EDIT: I can see the log contents if I use sudo, don't know if that's relevant.
I see 2 issues listed by Pihole Diagnosis; if I click on that, I see no issues listed.
I restarted my R-Pi and the result is unchanged.