It just makes them do it twice. So, they allow and log into Patreon, but it doesnāt take them back to my site. They have to click on my site link again and hit allow again.
Can you disable all other plugins than Patreon WordPress and check it out again please. There is likely something that modifies redirection or link behavior at your site.
The only plugins I have are Akismet antispam and Jetpack.
Make sure to check out your htaccess, and your web host control panel in case there are any specific redirection rules or similar is set in a panel.
Also, right click on the āunlock with Patreonā button, and copy the link - and DM it to me from the forum. There may be some parameter issue in the link.