LRC Pixieset plugin photos are disappearing from LRC albums

I have many Pixieset albums published through the LRC Pixieset plug-in within the Publish Services tab. Photos are missing from the pixieset albums in LRC, even recent albums. I'm using LRC 13.4 version.

When I want to edit a photo from a certain event, I go to that folder and instead of having the hundreds of photos inside of it, it shows zero photos. Although none of the source albums are on the computer itself anymore, some albums still show photos from events, and some don't (picture). Please let me know if you're familiar with this or might have ideas. Thank you!