Strange question regarding IPTV buffering - Its a head scratcher ..

Hi All - I wonder can someone help with a really strange situation.

- My IPTV devices buffers in my house.

- If I bring my devices to my neighbours house they don't buffer.

- If I bring my neighbours devices to my house it works fine.

- I have reset routers and all devices.

This occurs with android box, Vuz box etc.

I just don't know what it is - any ideas?