Zed f9p rover module not working as it supposed to

I got myself two ublox f9p modules: ZED-F9P RTK GNSS receiver board with SMA Base or Rover (pinout is on this page)
on your RTK guide you saying that it should be mostly plug and play.
and the base station - connected via USB to QGC, works just fine;
but im having problem with the rover. px4 docs “hardware setup for Rover RTK Module” says “most are connected via GPS port”

i soldered my wires like this:
GPS 2 Port ELT0087
1(red) VCC +5V 12 +5V
2(black) TX1 (out) 4 RXD (in)
3(black) RX1 (in) 3 TXD (out)
6 (black) GND 1,2 GND

I also tested with the I2C pins connected…

but it simply refuses to work; no matter what i do… digging the docs; i see its actually mostly inclining towards the CAN port;
and the only RTCM parameter; is also actually the UAVCAN_PUB_RTCM … so, i wonder if I should have used the 4pin, not the 6pin; and maybe the part in PX4 docs that directs users towards GPS port, is a outdated or something?
Both chips work fine as the base station; but neither one shows any activity when connected to the Pixhawk (6c)

Big thanks in advance! :slightly_smiling_face: