Sorry for being confusing let me clarify:
* If you disable the Facebook and Instagram plugins, the login buttons for other social networks do not appear on the front-end? I'm not sure what you mean by "all other providers have disapeared".
Yes login buttons of any provider do not apear on front-end in login module.
* When you re-enable them, what doesn't work? Authentication with FB and Instagram or authentication with the other networks.. or something else?
When I go to plugin manager and disable all of them and enable all of them they apear on website as if nothing happened.
* You are able to fix this issue by enabling the FB & Instagram plugins and removing their API keys? After removing them, if you disable those plugins, the other social networks continue to work as expected?
Yes when I remove keys other networks are up and running and visible on front end.
Last but not least if I click on Enable button at any provider nothing happens in jfbc, while in plugin manager I see them enabled but in jfbc they are not, I mean configure button is not visible. If I disable and enable them in joomla plugin manager confire button in jfbc is clickable.
Hope this clears it
Also in pinterest app link Where do I get this is broken (
www.sourcecoast.com/ext/pinterest-app-setup ) is something changed at pinterest like login/register being discontinued?
Thank you Alex!