Everyone above that says power is probably correct!

I was having a similar issue and the best that I could come up with was buying a larger power supply to plug my dongle into.

Instead for like $5 more or so, I found a refurbished DeX docking station and it works flawlessly. I did also buy a USB-C extension cable so that I didn't have to keep my phone in the dock and I can use it normally.

DeX Dock: https://www.amazon.com/dp/B0788F8DKC?ref=ppx_pop_mob_ap_share

USB-C Cable

https://www.amazon.com/dp/B07QKJWW1H?ref=ppx_pop_mob_ap_share

Good luck!