Not All my monitors show up in DisplayLink

[Marcocult]

Hi there,
I've connected three monitors to my Mac Pro M!, but I can only see two in DisplayLink:

As you can see by the image attached, the Acer ET322QK is not showinf up (the S22B300 is the little sliver you see in the Displays window).

Any idea how I can make it show up?

I'm using a Dell Universal Dock UD22 to connect the monitors to the laptop.

The real reason I'm asking, it's because I'm trying to connect a fourth monitor with the USB-C Thunderbolt on the UD22 but I don't seem to make it show up in the M! at all. I was only able to set it up as mirror of one of the others, but again, it doesn't show up in the DisplayLink interface. I only always see only two in it.

Any pointers would be appreciated.

Thanks!