Cannot login after downgrading from v2.2.0 to v2.1.1

[john-dupuy]

Env Details:
Ubuntu 20.04
QGIS versions tested: 3.24.0, 3.16.0

Steps to reproduce:

1. Install QGIS plugin v2.2.0
2. Login to plugin
3. Plugins>Manage plugins>Downgrade Planet Explorer
4. Try to login to plugin

Expected results:
4) Login should happen

Actual results:
4) Login doesn't happen (no info about why it failed)

Note: the login works in v2.1.1 if you restart QGIS. This issue corresponds to the jira ticket with id: PE-44613.

[volaya]

This is likely a problem with the QGIS update mechanism. Plugins are known to have this kind of issues when up/downgrading, since QGIS does not fully unload the previous version, so the new versions does not start from clean, and a restart is needed. Also, I suspect this might have to do with the main client class that deals with login and communicating with the API being a singleton.