Comment 9 for bug 1879645

I tried with juju 2.8 and couldn't reproduce.
Then with 2.7 I could reproduce.

So far, I have found that one of the vault units is not recorded as having left the relation in the offering model. This blocks the removal of the relation between the offered application and the remote proxy to the consuming app in the offering model. You can see that the relation is still there in the offering model by running juju offers. Note such cross model relations are not shown in status --relations.

You can force remove the offending relation by using the numeric id shown in juju offers.

$ juju remove-relation 1 --force

Once the relation is gone (force takes up to a minute) you can relate again successfully.

So the issue is why did only one of the vault units leaving scope fail to be communicated to the offering model. Interesting that juju show-status-log shows that all the relation departed/broken hooks have run; it's just the final cleanup that is not getting propagated, and until this step is done, the relation remains in the offering model. There's no such issue in the consuming model since the remove was done on that model and the processing happens locally.