Thank you @cdu13a for your kindness and clarifying answers.
In conclusion, it could be said that for running video files with HDR content it is better to use a box with S905X3 than S922X on SDR TVs, at least for now, both on Andorid 9.0 and CE 9.2.2 (same kernel )?
Is it possible for some next kernel to make some adjustments to make improvements in this issue?
On the previous CE (9.2.1), until a few weeks ago, in a kind of compromise the playback of HDR files was better, but there were other problems described very well by @pepeq here Problem with tonemapping HDR-to-SDR mapping on N2
Thanks.