apparently you got lost here somehow
The main support discussions are here: ODROID Forum • View forum - LibreELEC - Kodi Project
I described the same tearing problem here: ODROID Forum • View topic - CEC Questions and Issues
As you stated already, tearing is related to some changes introduced with LibreELEC-Odroid_C2.aarch64-7.0.2.use.Kry.Pulse8.tar testbuild.
A fixed build is on its way according to a post from wrxtasy in above mentioned odroid subforum. Just keep an eye on the main thread in odroid LibreELEC subforum.
I read wrxtasy's post in the odroid forum about a new libreelec subforum and immediatly tought of this one.
Thanks for taking the time to point me in the right direction.