The one on the left is a continuous wire with a little insulation striped off. Removing the one on the right did not let the trip come back on…The problem is that from that photo nothing can be deduced about what might be wrong.
IF the permanent live to and from the switch is as I've highlighted with red dashes
View attachment 391311
then what we'd be looking at would be a perfectly functional 4G switch with 4 outgoing switched lives.
If you disconnect one of the grey-sheathed wires I've highlighted, will the trip switch then turn on?
Can you post a photo of the back of the dimmer switch?

