Keyboard shortcut hold down does not work

Since the software (ESO) does not know the § key, I have declared the "§" key with the abbreviation "ü". The problem is that holding down doesn't work. ESO distinguishes press and hold.

Macbook Pro with Touchbar permanently closed.
Connected to Razor eGPU and external Screen.
External Mac Bluetooth Keyboard
Logitech MX Master 3 Bluetooth
BTS Version Version 3.938
MacOS 11.7.1