Is there any chance a bleed will cure it?

Nope 👎
Full rebuild for squish

Is that the 200hr service?

Oil height reset required. If you’ve got it stripped enough to do this it makes sense to service it & change the IFP at the same time.

Yup, it doesn’t actually need new parts but fixing the squish means doing 9/10ths of a full service anyway so there’s a good argument for going all in.

No point in “upgrading” the IFP though, Rockshox have released at least 2 “upgrades” which are supposed to fix this issue and of course it’s bollocks, the latest one is exactly as bad as the first one. You just hear less about it now because fewer people buy Reverbs (and they’re not as ubiquitous as OE)

TBH if it’s in warranty then it’s a warranty job. If it’s not in warranty, there’s better posts now that won’t let you down like a Reverb probably will. I got rid of all of mine once decent inexpensive competitors existed- I’d rather put the money towards a better product than service one.

Try turning the bike upside down, pushing the dropper down and then releasing, do this several times and it seems to sort the squish!
It was on the home page a few yrs ago

No point in “upgrading” the IFP though, Rockshox have released at least 2 “upgrades” which are supposed to fix this issue and of course it’s bollocks, the latest one is exactly as bad as the first one. You just hear less about it now because fewer people buy Reverbs (and they’re not as ubiquitous as OE)

Without derailing the OP’s thread I’d disagree about the IFP. The original aluminium IFP’s could fail  after the posts had been in use for for a while. The SKF blue & grey seals were a major improvement. Can’t say I’d be stripping the post to the extent required without addressing the IFP & worn bushings as a minimum.

Got a nice surprise working on a new C1 version last week. Expected to have to do a full service but they’ve put a vent valve on it to remove the squish. Worked a treat