Did that Wavlink docking station come with an external power supply..?
If so, then make sure that the external power supply is connected and working.
If not, then return it and get a hub to dock that has an external power supply.
Do other USB devices work connected thru the Wavlink docking station..?
If so, then there may not be power to support multiple devices and the printer.
If not, then return that docking station and get a different USB hub or dock.
Does the Canon printer work connected directly to the new iMac using a USB-C to USB adapter..?
USB-C to USB Adapter - Apple
If the Canon Printer is recognized on the iMac 's USB bus (Apple > About this Mac > System Report > USB)
Then try resetting the iMac's Printing System and re-adding the Canon Printer.
Reset the printing system on your Mac to solve a problem - Apple Support