..I’m with Roy. Wherever I see these type of crimp connectors (and wretched Scotch type) I bloody sigh and just cut them off / re terminate the wire with quality crimps..... because in all my experience they are just trouble.
Before this thread I honestly didn’t know that you could actually crimp these connectors reliably .... you live and learn.
(But I won’t be changing, even if can be crimped ok they kinda look very DIY & naff!)