bayron cold
This problem pops up now and again. Nobody has ever really found the answer or what causes it
It could my a multiboot image issue
It could be a memory issue.
Your box could be weirdly caching the entire etc folder and reloading it on a reboot. (possible if using a multiboot setup)
Some people have mentioned that gutemines software deletes or blocks other peoples plugins.
You can try adding your iptv, then rebooting your gui. Before you ever do a full reboot.
Also in main settings there is an option to save the playlists.txt file location.
Just change it to somewhere other than your /etc/enigma2 folder.
i.e external media like your usb