My new wipperman chain hops on the split link when it passes the smallest rear cog on the cassette.

I’ve made sure that it’s orientated as per the instructions and tried it in both orientations + inverted.

Cassette is new with bike, though i upgraded the chain as the stock Shimano split in 4 different places on a couple of back to back rides. Considered that that i might have a bent cassette tooth, however it’s only effected on the split link.

Any suggestions?

Bent tooth I reckon, exacerbated by the slightly different profile of the split link.

Are you using the right size of split link? They come in 8/9 & 10 speed flavours.

FWIW I always use Wipperman split links, have done for years with no problems on 9 and 10 spd stuff.

Yes, it’s a brand new 10spd chain with 10spd link. Will try and source a different cassette and see if it’s the teeth.

New to Wipperman, hence initial skepticism.

I’ve had this happen with the wippermann connector, cheaper to buy a kmc quicklink which will solve it.

Have you tried it with the link the other way up from what you have at the moment

Used there chains for years with no issues

Link is either upside down or you may have the wrong lock ring for the cassette – both of these will cause the link to jump on the smallest sprocket.
Had it years back when I got my lock rings mixed up – put a lock ring from a 12 through cassette onto an 11 through cassette – bigger diameter lock ring caused the link to jump. Maybe they have fitted a larger diameter lock ring from a 12 through cassette?
Used Connex links on lots of different bikes for over 8 years without a problem -apart from the above mix up.