Faced the same issue. Please help
I'm using an HP laptop and HP Universal Dock G2
Code:
Operating System: Linux Mint 20
Kernel: Linux 5.4.0-59-generic
Architecture: x86-64
GRUB_TITLE=Linux Mint 20 Cinnamon
I have two HP laptops and a newer one has an option in BIOS called "Enable High Resolution mode when connected to a USB-C DP alt mode dock" (it makes my USB 3.0 ports work like 2.0 but monitors work's on login) and it fixes this issue, but the older laptop doesn't have this option in BIOS...