In VenusOS 3.70 i had the same problem with it only showing RGB controlls. I haven’t checked yet, but i suspect that the Shelly pro RGBWW PM still isn’t supported in v3.80. Will check next week. I hoped that i would be added in v3.80
See this reply by @rzee from Victron explaining it.
I hope he might be able to shed some light on the current RGBWW situation.