The first thing that is done when S/R is started on a project is a commit to save recent changes to project history.
You can simulate this by using “Mark point in project history”.
I have seen cases where this takes a long time when a change is made to a large file - even a couple of hours in the worst case I’ve seen.
We use Mercurial for project history and there isn’t a good work around other than letting Mercurial complete the commit.
John+Wickberg
Paratext Support