I have the exact same issue! I have mouse and keyboard connected via dongle to the i-tec Nano Dock and they keep on disconnecting (freezing) a thousand times during the day. It's unbearable, and a real barrier to work, particularly if I'm presenting something. I have another docking station from Dell where I can plug keyboard/mouse the entire day with no issues. Also if I plug the dongles directly to the laptop there are no interruptions the whole day. It's really a problem of the i-tec Nano Dock. I reported the problem to Galaxus and they sent me a replacement unit, but the exact same thing happens. Were you able to fix this somehow?

Hello
I think this has to do with the power supply via USB-C. At best, the mouse and keyboard together need more power than the connection of the tablet or notebook provides.
Try connecting an additional (simple) power source, e.g. a mobile power supply.

Hello
I have a usb keyboard, an hdmi screen and a usb c laptop connected to it.
My mouse is in Bluetooth directly on the laptop.