1) Same issue seen with a complete new install of ubuntu-server-20.04 for pi 4 + Lubuntu.
2) If I do not include `dtoverlay=vc4-fkms-v3d` in \boot\firmware\usercfg.txt the lag goes away. However this introduces random screen flashing and other screen update artifacts such as blank regions.
A little more information that may help:
1) Same issue seen with a complete new install of ubuntu-server-20.04 for pi 4 + Lubuntu. vc4-fkms- v3d` in \boot\firmware\ usercfg. txt the lag goes away. However this introduces random screen flashing and other screen update artifacts such as blank regions.
2) If I do not include `dtoverlay=