When I first implemented Deps support, it used an IntelliJ API which gave me a lot of problems. I fairly quickly moved off that API to the same code which I use for the lein integration, and there was a migration which would automatically translate the old project files to the new format. The API supporting that migration has changed in annoying ways in 2020.3, so after a couple of attempts to fix it I've just deleted the migration. If you have older projects created in that short period of time, you'll have to re-import them if you're using 2020.3+, sorry.
When I first implemented Deps support, it used an IntelliJ API which gave me a lot of problems. I fairly quickly moved off that API to the same code which I use for the lein integration, and there was a migration which would automatically translate the old project files to the new format. The API supporting that migration has changed in annoying ways in 2020.3, so after a couple of attempts to fix it I've just deleted the migration. If you have older projects created in that short period of time, you'll have to re-import them if you're using 2020.3+, sorry.