Comment # 78 on bug 93826 from Scott Moreau

This also happens to me exactly as described in comment #75 when running a
freesync monitor @75Hz. The problem is fixed with high or low dpm setting as in
the comment, auto setting has the problem. This is with kernel Linux desktop
4.20.0-rc1 #1 SMP Wed Nov 7 00:30:18 MST 2018 x86_64 x86_64 x86_64 GNU/Linux