I set a 20 character password using Find My Device, but the lock screen only accepts 16 I used Find My Device to set a 20-character password for my phone (it accepted the password without any error messages as shown in the picture below). After I got my phone back, I went to type in the password on the lock screen, but I could only type in 16 characters.


  


I saw on Password too long to type in android device.Locked out from android device manager that mentioned the lock screen would accept the truncated password, but my phone does not unlock with the truncated, 16-character password.

I don't want to resort to a data erase, since I have important texts and memos, and also some contacts I don't want to lose. Is there any solution to this?
For other people with this problem - I found out that sometimes the manufacturer of the phone can unlock it or even back-up your data before a factory reset, if you go to one of their service centers.
In my case, my phone is a Samsung, but my local service center still couldn't do anything because my specific model number wasn't supported. They said they support the "popular" models like the Galaxy S series or the Note series.

So the first step would be to contact the manufacturer and see if they provide repair services for your phone. Otherwise, after this past week of research, it seems the only solution is to factory reset and wipe your data.