As an interesting experiment, take a connected bluetooth speaker and put it in a microwave oven (without turning it on, and if there is any question of it being on, unplug it).
You will find that the bluetooth connection is instantly broken by the shielding when the door is closed.
Bluetooth also has to put up with leaky microwave ovens, in addition to other users of the 2.4GHz band.
I just put my iPhone 13 into my microwave while playing music on my AirPods Pro. They kept playing reliably until about 10 feet away, where breakup started occurring. By 15 feet the connection was gone. Walking back into the 10 feet range the music started again though.
You will find that the bluetooth connection is instantly broken by the shielding when the door is closed.
Bluetooth also has to put up with leaky microwave ovens, in addition to other users of the 2.4GHz band.