Lagging issues with some channels, although fast internet

Hi,
I’m encountering some issues with some of my IPTV channels.

Some of the channels are perfect. No lagging at all, other ones are really annoying.
And it’s not like it’s the HD channels struggling. Often they run perfectly well, where the SD channels might be lagging.

I’ve got 100mbit download, so speed shouldn’t be an issue.

I found another thread elsewhere on the net, where someone said that disabling amcodec might work.
I’ve done this and it looks like this might have fixed it, but the stream is not looking as smooth anymore.

I’m running Kodi on an Android box (Beelink Mini MX S905 2GB/16GB) connected to the TV.