We have both Epson 9900 and P9000 for contract color.
Frequently ink cartridges that have been use become unrecognized by the either printer.
Sometime reseating them help temporarily.
We use always use Epson inks.

Anyone else have this problem?

Only thing I can think of is the inner contacts and sensors. If they are a bit dirty or the tiniest bit out of place you'd have trouble. Maybe a service call is in order. See what Epson thinks.

I had this problem with a batch of light cyan cartridges on our Sure Color P8000. I think the chips were faulty. Fuji replaced them and I think the 3rd or 4th cartridge was fine again.

You can kind-of help by putting a sheet of cover stock under the cartridge to lift it and make it make full contact with the chip reader, but this only worked for a few prints before it would decide it didn't like it.

So we got 2 new cartridges in to test and the P9000 was happy with the new cart. so we're good there.
The 9900 rejected the cartridge so it looks like service is needed on that device.

(Coincidentally it is VLM ink acting up on 2 different model printers)

coincedence? I think not!