I was troubleshooting Bluetooth connection today and I thought that this is somehow related to software (PipeWire, bluez, bluetoothd and all that stuff). But no. Apparently Bluetooth barely works when WiFi antenna is disconnected from my ASUS motherboard.
Anyway, this might save a lot of time for someone, so I’m posting it here.
Wifi and bluetooth are often on the same chipset and share the antenna. You’ll see this on embedded devices as well.
To add: Bluetooth and WiFi both use the 2.4ghz spectrum. They are on the same chipset because otherwise you would need two antennas
same frequency, 2.4GHz, same antenna, quite often for chip that does dual wifi/BT the antenna is shared