I haven’t logged in in a few weeks until today. I’m writing a post from a copy of the last post and it says that I can no longer choose the tier to gate the post for because I am considered to be in the Lite Patreon plan, but I’m in the Pro plan and have been for years:
Older posts show the same message.
Patreon Wordpress plugin Version 1.8.4
Does this go away if you disconnect/reconnect your site from Patreon?
Health check passed, I cannot reconnect. Followed advise given by plugin and created new API keys, can’t connect, end up with this error:
{"errors":[{"code":3,"code_name":"ParameterInvalid","detail":"Invalid parameter for 'oauth_client_id': 7800.","id":"06f4f99a-6301-5536-ad5a-4d46c5dd6515","source":{"parameter":"oauth_client_id"},"status":"400","title":"Invalid value for parameter 'oauth_client_id'."}]}
Trying to connect with the new settings recreated the old API key I had deleted. I refreshed it and entered it again and now the connection is up.
All seems good now 
I can choose tier for the posts again.
What I understand from your recent posts, it appears that your site seems to have lost connection to Patreon. So the plugin wasn’t able to get the tiers. When refreshed, it became able to get the tiers again.
I’ll take a note of this.