SUMMARY
The hour hand on the clock is one hour behind where it should be in the UK and the EU.

STEPS TO REPRODUCE
1. Select a UK or EU time zone
2. Observe the hands on the clock

OBSERVED RESULT
The hour hand is one hour behind the time displayed on hovering over the applet and in the digital clock if used.

EXPECTED RESULT
The hour hand would be in the correct position, as it was until this weekend.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 5.22.5
(available in About System)
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 5.10.52
Qt Version: 5.15.2

ADDITIONAL INFORMATION

Although the digital time is correct, it is misidentified as "GMT" when the UK is still on BST for another week. EU users have confirmed a similar problem. The GNU date command shows the time correctly as BST. The analogue clock in Systems Settings shows the correct time also.