Clipboard history not maintained

Describe the bug
The clipboard history is assigned to a trigger. However, copied items do not appear in the history - it remains empty. I have restarted my computer, hoping that would solve the problem, but to no avail.

Affected input device (e.g. MacBook Trackpad, Magic Mouse/Trackpad, Touch Bar, etc.):
Magic Mouse 2

Device information:
Mac Pro (late 2019)
macOS 11.3.1
BTT (1702)

Additional information (e.g. StackTraces, related issues, screenshots, workarounds, etc.): Let me know if there is anything else I can provide.