Clear cache
what device are you using? If its IPTV smarters use VLC for movies
It can be so much things first off whats your intent speed how big is the movies files you trying to watch and what type of device you have if you have a ton of apps on your device and dont have much space can do that ad well and what id great speed hoe much mgbps you have your internet provider can do that as well change the players as was said to you as well try using a vpn
try starting the movie then pausing it to let the buffer build -- ad sometimes when you do every thing right on your end the problem may be on the providers side ...
Pull plugs, while on, tv/wifi/firestick, reboot...
It could be your iptv provider servers, have you tried IM player.
Are the movies local to your network or external? Same subnet?
Not sure why your movies are buffering, I have an IPTV services, the general consensus seem to be to clear the cache (not the data) of the app, turn off the router and the TV box for about 20 seconds. Don't know if it will help but worth a try!
Alright so, I’m on Firestick. I don’t have anything installed really, I’m using 1.5gb of 5gb. I get around 80 download 20 upload. I purchased the fire stick pre loaded off someone so I don’t particularly know much about the servers it’s using. But it seems to be one called EMD.
It could be peering related. My plex server is in a datacenter with a unmetered 10gbit connection, I can mantain a full 1gbps from it but I have friends on different internet providers who when speed test to my server only get 1-5mbps but have 1gbps packages themselves. This is down to the provider having poor peering agreements or the ISPs routes aren't great. Easiest way to prove this is to change the route you take to get to the destination (VPN - over a provider you know you get good speed on, or selfhost from a cloud provider so you are the only one on the compute instance (shared connection, but vpn's typically have CPU limits on routing traffic)
That IPTV/VOD provider is likely the culprit. There are many bad ones out there, and they often strongly oversell what they have, almost like a scam because it works fine early on, when you buy, at first, then they sell to hundreds and the stream goes to crap. When too many people watch a stream, more than should, it buffers. Unfortunately you bought your Firestick preloaded and don't know much of anything about who the actual provider is, so there is really no recourse. Seems like you bought a bad service and might want to move on from these people if the problem persists.
I suggest you try other VPN server. Or no VPN at all. Just to check if it's related.
Also, try some other device if you have (eg. PC or mobile phone). Those test should reveal to you where is the problem. Good luck!
Are you using STBEMU on your firestick for IPTV?
Try changing players to VLC or mx etc for VOD