Huawei P30pro fails USB-HDMI recognition

Hi everyone, please help me figure why my new-ish Huawei P30pro won't connect to a HDMI screen using a usb adapter cable? My first 'help request' here!

#1 I can't see this handset recognised on Android forum? It gets auto recognised as VOG09

#2 this isn't going to a smart TV, just a HDMI screen - of which I have 3 or 4 variants of need be, of carrying she's but including a 4k model purchased in 2019.

I can see several YouTube reviews that suggest the worked connection works better than WiFi option, and this function was one of the key selling points for me getting a new handset. Previously I had a P10 only to find several of the features I thought were included were only on the pro version. Now the P30pro has USB-c 3.1, so should be a a synch...

Got a cable specifically for the task; Y cable with power-charging connection, plus the HDMI and USB-c connection.

#3 I plug it in, and phone recognised only same as though it was plugged into a PC:
'Do you want to - transfer photos, transfer files, charge, reverse charge..'

When what I really want to occur is the question I see on the YouTube: desktop mode or screen mirror.

Any guidance please?
Is there since built in app that needs permission I've not granted, it something?