ASUS DSL ac55u and Firestick incompatibility

Hi all,

A friend of mine has an ASUS DSL ac55u connected to ADSL2 from Unlimited Internet. When she plugs her firestick into her TV, the wireless connection drops on both 2.4 and 5Mhz and is unavailable to all other devices. Has anyone experienced anything like this before? Is there a setting on the DSL ac55u that I'm not aware of?

Thanks in advance

Mike