Thanks for providing these details!
Did you happen to generate a diagnostic when this was happening? If so I may be able to see what the issue was. I don’t think this problem was related to the version because we didn’t change anything in the sync engine between those versions. It sounds like it may have been a local database issue.
A repair install won’t help in that case because the install process just lays down the application files and doesn’t touch the local persistence. In the cases where the local database may have an issue you can perform a deauthorization to reset it, or an uninstall and reinstall. It sounds like you did the latter, but installed an older version. The uninstall removes the local databases, so odrive has to re-scan everything to make sure it is in sync, which is why it took a while.
Please let me know if you encounter any other issues and I can investigate right away. Our top priority is making sure odrive is working the way it should be.