SS IPTV

Hello,
I have a Samsung smart tv with Tizen (2020).
While pressing a channel it loads really slow until it goes live, which could take up to 1 minute.
Sometimes it loads a few seconds, but most of the time it loads really slow and can even not play the channel at all.
I'm trying my m3u on my iPhone and PC and it works perfectly, but not on SS IPTV.
What can I do about it? Could it be a port situation?

Thanks