[PROBLEM] freezes after a certain time of running

[menakite]

Does it get automagically fixed if you switch the TV off and on again?
What if you disable the CEC functionality in the TV, enable it again and then switch to the Pi input?

Also, try the following (via SSH) on the Pi:

Terminal

sudo tvservice -d /boot/edid.dat

Then add the following line to /boot/config.txt: hdmi_edid_file=1

While at it check that it contains this line - if not add it: hdmi_force_hotplug=1