Apologies, thought I had mentioned printer, lol, its an Ender 3 V2. I have always fitted the tubing as per the recommended way of, cutting square (I bought one of they tube cutter things, which does a neat cut), fit connector (upgraded black top type), tighten down, then release one turn back, push tube all the way in hard, then while doing so, re-tighten the connector. Attach clip. Print finished OK last night, but it usually takes a few before it starts again. This is with cheap tubing this time, and not the Capricon stuff.

Just ordered a Swiss DD with hotend, so gonna try that route, although not looking forward to figuring out all the offsets, as I'm pretty clueless that way

Thx for suggestions guys, much appreciated!