facebook log in pop up in multiple devices

So here's my problem. I made the mistake of changing my Facebook password cause of some suspicius activity which unfortunately it is to be expected. Then this caused an issue to begin in all of my apple devices and I do mean ALL of them. At first they popped up errors that my Facebook password was incorrect which was expected as I had changed it and I proceeded to enter the new password to all of my devices. For a bit it was all Fine. The password was accepted all was well. And then I started getting error messages that were like so: enter Facebook password for the app "my Facebook email" in settings. (Bear in mind i translated the error from Greek)

Those messages appeared in all my devices that include: an iPad mini 2, an iPhone 3GS, and a MacBook Pro 13" Mid-2012.

and here is where it gets interesting. I no longer use my iPhone 3GS and I was given a slightly used Iphone 4 which I restored completely and formed as a new iPhone completely from scratch. I logged in to Facebook no problem as i used the account with the new password from the get-go. After a few days I decided it was time to fix the Facebook issue with the rest of my devices so I tried some of the fixes which included deleting my Facebook info from my iPad (and I did it only there). What happened next? Well of course my iPad still pops up the message. And at the very moment my iPad popped up the message me NEW iPhone popped it as well! How is this even possible? Cause I never changed my password on my new phone.

some of the fixes I have tried with no result what so ever:

-deleting my Facebook info from my device

-reseting my privacy and location services, then tried to log in

-deactivating all the apps that use my Facebook info (even though I might add all those apps no longer have access to my info after deleting and re-adding my Facebook info in the settings)

-restarting device then try again

-restarting settings/preferences app then try again

side effects of this issue

-regular pop-up messages

-apps that use Facebook through the settings to log in can no longer do so (even before deleting my Facebook info, this was mostly the reason I tried to fix this issue)

-I no longer get notifications on my MacBook after pop ups (and I get them for a while after I re-enter my password until the message pops up again)

the Facebook app surprisingly works fine in all cases and so does the messenger obviously.

Notes:

-when i re-enter my password to my devices it is accepted, for a few seconds on my iPad, minutes in my iPhone and maybe even days in my laptop, or until they are needed in which case it pops the message again.

-there's no "wrong password" error of any sort.

-when I try to use Facebook info through apps Facebook blocks them due to "suspicious activity" which I make sure to settle and it does not block them again again even if the app still fails to log in due to the fact that "my device is not set up with a facebook account" which is no doubt due to the usual error and pop up. I don't see how the facebook block is related since it won't keep me logged in through setting for long anyway but I thought I'd mention.

-in the setting, in the Facebook tab, it says that there was a problem in communicating with the server And has a field to enter the password. like mentioned before it will accept the password and everything but once the message pops up again it will go back to the communication failed state.

-I sometimes have a similar issue with google account on MacBook but it must be some kind of glitch as it gets fixed with a device restart... The Facebook issue persists

-on MacBook the pop ups can be as regular as immidietly after I click settings to "fill in my password" like the preferences could be open and I still get pop ups. They are delayed with restart of the device but they come again in regular intervals.

seen a couple of threads on Facebook about this. It seems the issue is with the devices.

my question is simple. Is there even a fix?