I have a PDF in Devonthink. I opened the PDF in PDF Expert and made annotations. I saved the PDF, and closed it. I changed the name of the PDF in Devonthink (e.g., by force-clicking the file’s name through Devonthink, and then writing in a new one). I re-opened the PDF in PDF Expert, and all of my earlier annotations disappeared. The only annotations remaining were ones that were there from the day before.
What the heck happened?? How do I get them back? There were like 2 hours worth of annotations. 
(I realize this could be a PDF Expert issue, mostly I wanted to see if this were a known issue or if something about my own janky system caused this…)