It appears there is an issue with the Secret Lair cards that are marked as "Rainbow Foil" on the TCG website. For some reason, prices pull through in the Secret Lair Drop Series section of Editions & Printings, but the prices do not pull on the actual inventory. I checked numerous cards, and each one that had an issue was listed as a "Rainbow Foil" on TCG's website.

Example:
Acererak the Archlich inventory list pricing is N/A for TCG Player Market. The card has a listed price of $3.00 on the Secret Lair Drop Series section under Editions & Printings however, which appears to be the correct market price. There is some kind of disconnect between the price being listed under inventory, and the price being pulled for the specific "Secret Lair Drop Series' section.

Hopefully that makes sense!

Bumping this post as the issue still persists. Thanks!

I have fixed today some issues with a bunch of Etched and Rainbow foil cards.

Thank you!! This was a big fix. I appreciate all your effort.

Edit: I believe I posted about this years ago, but now that these Secret Lair pricings were fixed, the issue came back to my radar. This effectively fixed the price for almost every card I have, except for the Guilds of Ravnica Mythic Edition Planeswalkers. The prices for both the War of the Spark Mythic Edition and Ravnica Allegiance Mythic Edition work, so I would "hope" this would be a relatively easy fix.

If those were fixed, it would only be a handful of tokens in my 22k card collection that did not have a TCG pricing link!