Tivimate 403 and 406 errors

I'm not an advanced IPTV user. At all. But I am aware of the XC issue, and overall I've been trying to be patient, but I also want to make sure there's nothing I could be doing to get a better experience.

I use Helix, watching on Tivimate through a Firestick. I did a custom EPG thought iptv-epg.com

Right now, I'm getting 403 and 406 errors probably half the channels I try to use. Even more frustratingly, sometimes I'll be watching a channel fine, switch over to something else briefly, and then when I go back to the original channel, error 403.

So, is this just part of the pain of providers trying to figure out the post-XC world? Or do I have a problem with some settings or something? Any help would be greatly appreciated.