Apologies for the inconvenience caused!
We are actively working on this issue and will let you know once the fix is available in our upcoming release.
Thanks for your patience and valuable feedback!
An error occurred while saving the commentAndy White commented
I have this issue also;
1. Acrobat Version 2018.011.20040
2. macOS 10.12.6
3. Time to display comments panel: 30 secs (Current file has 33 comments)
However this is independent of the amount of comments contained in a PDF as it still takes 30 secs even when the PDF on my mac contains no comments.