I have 4 x HK1 RBOX X4 (HK1/VONTAR differ only in name). All run great with the Vontar X4 slimbox 16.9 aosp rom. Never had a problem getting connected with a Dual USB cable to the USB 2 port to flash with Burning tool 3.1 . Only thing I found was that once flashed and booted I needed to open Magisk app and then reboot before root activates. At the end of the day most X4 boxes are pretty similar except maybe for 1GB /100MB ethernet ports. You get what you pay for lol
What version of HK1 Rbox x4 do you have? 32/64/128GB ROM? And is there any HK1 that's not 1GB LAN? I'm saying this because i've bought HK1 before (S905x3) and i got a damn 100M ethernet :x
I'm just asking if there are 100M boxes playing around claiming 1GB lan, i'm not very lucky and i always end up getting 100M no matter what i pay...