Facebook Login Error

Unexpected Error Occured. try logging in again

My account got forced logout then everytime i login to my ios device it keep saying "unexpected error try logging in again" , all the different accounts i try to open to my ios it says error, the facebook app, messenger but when i try to login to safari it connect and its okay. I tried to reset my network settings and privacy/location settings and tried to reinstall fb messger and ig to get the new update but still it says error. Its been 5months since it started error. Please help me, my iPhone 6s is up to date too, all updated but still unexpected error. works on other device but this device started error when force logout. Please help me, thank you so much!