The CLD-Dx01, CLD-Dx02 can have eject problems ranging from not being able to eject at all to struggling to eject. I believe this might also be applicable to the CLD-2090/3090.

If the belt looks good, it it is probably the grease Pioneer used that has turned into sticky, dark orange goop. To properly resolve this, the clamper needs to be removed, cleaned, and then white lithium grease applied to where the old grease was. The rest of the loading mechanism can benefit from this as well (particularly the slide cam, but I do not have photos of that).

1. Remove the two screws (already removed in this photo) and retaining clip.

2. Remove this assembly. It consists of 3 distinct pieces.

3. Extend the clamper enough to expose the screws on each side under the white plastic clamp cams and then unscrew them.

4. Retract the clamper and remove the clamp cams for each side.

5. Remove the ends of the clamp lever that were held in place with screws. Now remove the other clamp lever by sliding it up.

Disassembling it is a relatively easy process
getting it back together is where things could got tricky

I've been having eject issues on my two Denon LA-3100s' for quite some time and assumed it was always the clamper magnet being stronger than the Pioneer units I have (which may still be true). Thanks for the advice and definitely will try this out.

Magnets are too strong it seems even on the Pioneer-badged units. The entire loading assembly needs a cleaning and re-grease as well + new 4.0ish belt.