Spent 12yrs as a connector design engr and manager for AMP (now Tyco) and JAE and have Patents on connectors (for Medical products) so, connector talk interests me… And, I often worked with Molex, Lemo, Takata… I love connectors!
Those red guys in the photo could be most any brand, we made many that look just like them - but, not the same…
I looked through my boxes of connectors but did not see 6 pin guys with similar latching.
Connectors are all about the Normal-Force between the contact surfaces, and a host of things will affect that good, consistent continuity.
If it were me, I’d consider making Pigtails with contacts on wire or replacing them.
A cheap, but useful approach is to put contact on wire and goop them-up with Hot-Glue - not a pro solution but, we often did it for quick testing (top one in photo…) Don’t melt the wire insulation!