Accessibility Tags missing when Combining PDFs

[sandra_0619]

I have a PDF with 5 appendices that need to be inserted. All appendices were remediated separately and when it comes time to insert the into the main PDF, the tags go missing in the combined file. I double checked that the tags are in each indvidual file but when combined they disappear for some of the appendix files.  
I have tried to combined the appendices separate from the main body and still no tags. I have tried to use the organize page panel and insert a few pages at a time to see if that works and still no tags. I was told to insert the appedix file at the very end of the file and then move it up to it's correct version and that still isn't working. Not sure what else to do and I'm running out of time and ideas to meet my deadline.

[sandra_0619 · Accepted solution]

UPDATE: I finally got it to work!!
I extracted copies of the dividers (B, C and D) that I needed and then added the dividers to the separate files (because when I tried to add the files to the dividers, the tags were still missing). Then I added the App C divider and placeholder page and checked that the tags were good and saved. then I added App D to that file, checked tags were good and saved. AND THEN I finally added it to the combined PDF and they finally stuck.