I am using MacOS 11.6.5 Big Sur with MX Master connected to Bluetooth.
Without Logitech Options+ Software the Mouse button is recognized as BT4.
With Logitech Options+ I have reassigned this Button to a Hotkey Shift+Ctrl+K,
but Teamspeak recognizes neither the original BT4 nor the new Hotkey.
Teamspeak 3 is enabled in Secutity Settings “Input Monitoring” and “Accessability”