No signal/bad signal issue in 10bit YUV with CE 8.95.0 and S912

Hi all
I received today my first S912 box, it is a H96Pro+, claimed to be “2018 edition”, with 2Gb of RAM and 32Gb of eMMC.
I installed CE 8.95.0 with the gxm_q200_2g.dts. The box works ok, gigabit ethernet, WiFi, BT,CEC and remote (after keymap) are ok.
However I have problem with the color space. I connected the box, in place of one of my 4 Nexbox A95x (S905x) running Libreelec 7.95.x (kszaq build with Kodi 17.6), to my HDR 4k projector.
I set, as I was used to do with the A95x, the 444,10bit color space with

"echo '444,10bit' > /sys/class/amhdmitx/amhdmitx0/attr" in and reboot

After the reboot the VPR show “no signal”. With no colorspace override, CE boot fine and Kodi GUI is displayed at 4k, but the HDR movies are output to 8bit which is of course not good. So I tried to lower the colorspace:

"echo '422,10bit' > /sys/class/amhdmitx/amhdmitx0/attr"

Results in signal detected but still YUV 8 bit, and Kodi GUI and movies are displayed with green dominance

"echo '420,10bit' > /sys/class/amhdmitx/amhdmitx0/attr"

This works. GUI and movies are in YUV 10 bit with correct color
Now, the YUV420 is the default color space for all the bluray movies, but suboptimal for RGB video (in reality only demos are encoded in RGB or something more than 420).
So, can anyone confirm that CE 8.95.0 is ok for HDR and in general 10bit colorspace? It is possible that i have a problem with my H96Pro+, but it is strange that 422,10bit result in YUV 8 bit with green dominance displayed by the VPR.
HDMI cables are ok, because they worked with S905x and also work at full 18gbit speed with my Xbox One X (YUV 420, 10bit, 4k, 60Hz)
Thanks, bye

Check refresh rates for 10 bits here:
If you use 60Hz, than you can receive no signal.

422 green issue will be fixed in next release.

Ah right! So the color space setting is applied to the GUI also, now I start to better understand all the discussion about the automatic color depth switch (that apparently was supported in some way with kszaq builds).
Anyhow, with GUI set in 30fps, and whitelisting the playback resolutions I need, which is required in order to make frequency switch work, everything is ok even in 444,10bit (of course you must not whitelist any 4k resolutions above 30Hz).
Honestly with the limitation of HDMI 2.0 and without automatic color depth switch, I am more to set 422, 10bit.