The SecretsManager seems like something that would be a model version vs controller version incompatibility. (We shouldn’t have those, as they should stay compatible, but that is the sort of mistake that could be made.)
“not the leader” is reasonable, if there is another unit that could be leader, but if there is only one unit that does seem like a problem. And cannot create relation state tracker seems a bigger issue, as that seems like the Uniter thinks it is the leader, but then the controller turns around and says that it isn’t.
For the former, it seems like juju upgrade-model should fix it. But it would be good to submit 2 bugs. One related to SecretsManager incompatibility and the other for cannot create relation state tracker.