We hear many complaints of people watching IPTV by using an app on their Smart TV. Instead of using the EPG of the provider, SIPTV uses their own EPG-source. That causes the disadvantage that in many cases the EPG is often incomplete or incorrect.
Another issue is that when people use the IPTV app on their Smart TV, there is an increasing interference or malfunctioning channels.
So be very careful using such apps and certainly do not use them as your prime Player for your HIPTV subscription. It is preferable to use Kodi, or similar app of your choice, on an Android Box. That generally works much better and seamlessly.
So before you complain about your IPTV provider, first check carefully whether similar complaints occur on different IPTV Players, like e.g. Kodi or VLC Player.