Conflict with theme and adding header/footer code

I've disabled all plugins on my staging to troubleshoot excluding only (GP Premium, UM, Elementor Page Builder, and WooCommerce).
http://bke.1a0.myftpupload.com/login/
I've also followed the instructions at the link you provided to add via the p_body_open hook (appearance -> elements method) and still not working. If I switch the theme away from GP though it works :(

See anything interfering?

Does the same login work on the staging site? Trying to login but it's telling me the password is incorrect.

Sorry I think I had the password changed since sending it to you. Resetting it now. Do you have an email I can send the credentials to?

Our Account Issue form is best: https://generatepress.com/contact/

Ok I've sent the credentials. Do whatever you need to do in order to troubleshoot. This site is purely for testing.

Is the issue happening right now? I just logged in on that page with no issues.

Let me know :)

The issue is happening right now. When trying to login here http://bke.1a0.myftpupload.com/login it's supposed to log you in and redirect to the my account page but it's not. I log in and try to access the account and I cannot because it's not logging me in.

It's consistently logging me in, but it's not showing me as logged in until I go back to the login page.

I took a look at your response headers and the login page is cached: https://www.screencast.com/t/sLQUuoDmao

This means you likely have some server caching going on, which is why it doesn't look like it's logged you in - the non-logged in site is cached.

You should:

1. Turn off caching on the /login/ page
2. Turn off caching for logged-in users

We do the same thing here on this site.

How would I go about that? I don't think I have a Cache plugin in use on this site.

It's likely on the server-side of things then. I would contact your hosting support and ask them to turn off their caching for that page (login) and for logged-in users.

Is it possible to do that for an individual site on a shared hosting server?

Honestly I doubt my hosting provider would be able to do this. They never seem to know what they're doing. Perhaps there's another way.

If it's not possible to deactivate the cache for logged-in users, you're going to run into all kinds of issues while running a membership site (including being able to log in properly). That's why all cache plugins have a "ignore cache for logged-in users" option - it's essential for 99% of membership sites.

I can install one. Which do you recommend?

It won't help in this case, as caching already exists on the site. That's the caching that needs to be disabled or altered.

Your hosting should be able to disable it at the very least - I would be very surprised if they forced server caching on you.

Do you know the source of the caching on the site because I don't have a plugin installed and as I mentioned above, I turned most off to troubleshoot the issue. I can give my hosting provider a call this evening.