Page Designer - "Field deleted" on PDF export

I’m encountering a strange bug with Page Designer and the PDF export. Some dynamically filled values export as “Field deleted” on the PDF although they are showing up perfectly fine within the plugin (and are not deleted ofc). The fields do show up properly though when using the print dialogue.

This is how the preview within the Page Designer plugin looks like:

And this is how it looks on the exported PDF:

As you can see, some fields work just fine and others trigger the bug without any recognizable pattern to it.

This is on Self-Hosted DE 3.1 with Page Designer 1.0.99

Also the Page Designer plugin seems to have a problem with PNG files on export. They look OK in the preview but generate problems on PDF export. Mostly resulting in no export happening at all.