State Mismatch conflict w/other plugins

When I have the plugin active, it blocks certain other plugins from using api’s, giving a “State Mismatch” error showing a “back” button. For example, activation of Elementor’s pro feature requires connecting its plugin to the site, and when active PrivateCalendars blocks this with “State Mismatch.” The same happens with the “Use Your Drive” plugin when it tries connecting to the Google API – it is blocked by PrivateCalendars with a “State Mismatch”.

When I hit the “back” button on the “State Mismatch” error screen, it goes to the PrivateCalendars settings screen (even if I started somewhere else).

When I deactivate PrivateCalendars, then the “State Mismatch” error no longer occurs, so it is definitely caused by PrivateCalendars.

I love the plugin, but need to avoid this problem. Turning off all calendars on my site to activate another plugin is not good.

BTW – I would like to use just the API key rather than oauth, because I only use public calendars with the plugin. It might avoid this problem. However, trying that does not work for me, it will not actually retrieve any calendars without setting up oauth.

Thanks!