No HDMI signal from new Manjaro Community Edition phone dock

[wibble]

Could somebody please explain this:
The same monitor using the same HDMI cable but branched to an ordinary X86 PC always worked. So I just wonder what makes the difference??

Different hardware, different driver, different platform and possibly different HDMI version. There's quite a lot of scope for little differences to cause a problem. I'd be more interested in the differences between the monitors that work and the ones that don't - that might help narrow down the possible cause(s). Are the HDMI versions different? Does it only happen with certain resolutions, refresh rates etc? Is there some EDID data quirk?

Of course there is very different hardware in all the monitors and most probable different versions of HDMI.
But with all the X86 systems and all the monitors I have used there was never ever the slightest problem with HDMI output. Therefore my conclusion is:
The PinePhone with the dock delivered has not been sufficiently tested before and we are the paying guinea pigs of pine64.org who once more does not at all care for customer satisfaction.

Sorry - I mistook your post for a serious query.