I’m facing a similar issue.
I found that by going to version 1 and clicking through each version one-by-one gets me back to where I left off.
Kinda seems it adds changes from each version one-by-one when I do this. If I skip a version as I iterate through, I don’t get the changes from that version and in some cases that would wreck the project as later versions depend on the changes from that version.
It seems version diff tracking is completely broken and it doesn’t matter if Github is linked or not.