On the question of not updating the system if everything works, I absolutely agree.
I found that with Matrix 19.4 RC2 in some channels the recording gives me this errors and then creates problems in the playback.
With Leia everything works very well, I reach 5 simultaneous recordings and the temperature remains good, and I can watch one of the 5 recordings while they are in progress (all IPTV) and the cpu temperature remains stable at 50 degrees.