I recently got a 90mm cam for my top RF Pacemakers; works fine with my Angulon (lucked out on the FL match).

BUT...when I tried to fold the camera there was resistance from the inner portion of the yoke, which did not seem to want to retract all the way into the body. I noted that the RF plunger at the yoke was not retracting all the way; evidiently the cam profile would not let it do so. Thus the camera cannot be folded with the cam installed. Which is annoying, to say the least.

I do not remember anyone saying anything about a problem like this; is there something out of order with my setup?

I would suspect cam seating in the track. All cams have two dents that form tabs on one side that have a flat side to the rear of the cam, make sure that both flat sides of the tabs are against the cam tube/track.
On Top RF Pacemakers if you focus too close to an object then the cam comes out from under the cam follower arm and jam against it on returnint to infinity or close. Remove and reinstall cam each time on returning from closer than 6 feet focus distance, or manually lift the follower arm and allow the cam to silde under it.
Charles