There are lots of factors that can affect the FB login button. Plugin conflict, Device issues, Browser issues, Own FB Profile configuration issues, Site APP Configuration issues, and tons of others. There maybe many wpForo users who got such problem, it doesn't mean wpForo works incorrect. wpForo does nothing, it only loads button based on your provided keys, nothing specific and hard. The code which display buttons is provided by Facebook Developers, we just copy and paste in plugin. So this problem is most likely (99%) not a wpForo issue. We don't have access to personal FB accounts and settings, so it's hard to help you.

We tested on different mobile browsers and it works fine on most of them.

Left: Chrome | Right Safari

Hello Robert,
Here we have all our settings, in the picture

https://wpforo.com/community/how-to-and-troubleshooting-2/login-problems-with-facebook-api-vs-website/#post-13058

the redirect does not work when you are logged in

What do you mean saying this? The redirection works one time right after login process. If you're logged in there is no any redirection.

One post back frome you, you say this;
We don't have access to personal FB accounts and settings, so it's hard to help you.

And i say:
Here we have all our settings, in the picture
https://wpforo.com/community/how-to-and-troubleshooting-2/login-problems-with-facebook-api-vs-website/#post-13058

Are these settings correct?

At the moment I'm talking about wpForo redirection function once you logged in.

We don't have access to personal FB accounts and settings, so it's hard to help you.

This is related to FB button issues.