Issue with Firesticks

Maybe not the right sub but I'll ask.

I currently have an IPTV service that has their own app.

On my phone, it never buffers.

On my Firestick in my daughters room(roughly 30 ft from router), buffers once every 15-20 min.

On my Firestick in the living room(literally inches from the router), buffers once every 2-3 minutes

I have 30 MBps download. I will play the same channel on all devices and what I wrote above will do. My phone is a LG G3 so it's not very powerful. Both Firesticks have been factort resetted so nothing but the IPTV app on them.

Any ideas/suggestions?