I had exactly the same problem and I had real trouble finding a solution. Eventually, I solved it by turning off Gnome's automatic window scaling. You can check your current setting with the following:
gsettings get org.gnome.desktop.interface scaling-factor
If this returns a value of uint32 0, then it means you have automatic scaling turned on. I found that setting this to a specific value (in my case 1) fixed the issue, which you can do using the following:
gsettings set org.gnome.desktop.interface scaling-factor 1
I discovered this by following this answer about scaling gnome's login screen. The problem seems to be caused by a mismatch between the login screen and desktop scaling factors.
I had exactly the same problem and I had real trouble finding a solution. Eventually, I solved it by turning off Gnome's automatic window scaling. You can check your current setting with the following:
If this returns a value of
uint32 0
, then it means you have automatic scaling turned on. I found that setting this to a specific value (in my case 1) fixed the issue, which you can do using the following:I discovered this by following this answer about scaling gnome's login screen. The problem seems to be caused by a mismatch between the login screen and desktop scaling factors.
You can upgrade dist too
sudo apt-get dist-upgrade
I'm sure this solution is working for you.