Android 10 the M40 and Android 11 the Plus/Pro.I am still stuck on android 8 on my M30, No upgrades, But it seems to have all the codecs, I supposed your M40 is on Android 10.
As i have said nothing really uses H.264 10-bit any more and what does can be found in H.265 format, So i would not worry about H.264 10-bit compatibility.
But it's not android. It is the "SPRD" codecs (which are the HW codecs for the tablet in question) that have been poorly and partially implemented despite the well-equipped GPU.
In Software it plays smoothly (except for stuff with over 10mb / s bitrate and 24bit FLAC).
The problem is that in my region they still use too much x264 10bit (they have the worm that they think is better x264 than x265 and they don't want to release in x265. I convert everything I can to x265 but I can't do miracles).
Anyway, nothing. Thanks anyway