Adobe Acrobat hangs slow when tagging PDF accessibility

Hi everyone and sorry if I am not posting in the right location. I am using Adobe Acrobat DC to remediate a PDF to make it accessible so I work a lot with the Tags panel, the Reading order window, etc. I am currently working on a 140-page PDF. My issue is that everything I do with the file takes an unbelievable amount of time. Even selecting a tag freezes the application for a good 20 seconds. I have a capable CPU and Adobe is barely using 14% of CPU and not even 2GB of RAM. Saving is also an issue, selecting an element with Reading order panel to tag also freezes the app. In one instance I selected a 2-line header to tag it as a Heading 2 and I had to wait 5 minutes. Is there something that can be done to fix this?

Thank you for your time.