Apple TV: wifi reception unstable after update to firmware 5.3

I recently updated my Apple TV (3rd gen) to firmware 5.3.

After this update the wifi network reception on the ATV became unstable.

The ATV firmware update was the only action which I performed.

My network consists an airport extreme with the latest firmware (6.3)

I don't encounter issues on all other devices connected to my router.

Are there more people who are experiencing similar symptoms?

Can somebody suggest a solution?

best regards,

Remon