Just a few tips I have on this, and I am a total newbie user but have been playing with it a lot lately.
Use the "Status" tab. View the sub-tabs for "Subscriptions" and "Streams"
Multiple Kodi clients connected to the same channel will manifest as multiple subscriptions to a single stream. The single stream is TVH connection to the external IPTV source.
The idea is to not allow multiple connections to the external source if not needed, they can all share it. Including the DVR feature if you use it. Also fyi under "Connections" tab see all your Kodi HTSP clients and their IPs whether they have subscriptions or not.
Keep an eye on the log (use bottom right double up arrow) window, you should see your Kodi clients connect and disconnect and which streams they are subscribing to.
