My advice? You're probably going to have to just wait and see what happens. I've dug into a lot of info and posts on here and I'm pretty sure it's something on Bungie's end. Lots of solutions and workarounds don't seem to fix the issues for the majority of players who experience these errors. The thing is, you don't even actually disconnect from Destiny 2's servers. It just kicks you to Orbit for something that happens in those game sessions, kinda like Guitar, except it triggers for a different reason and it usually only affects one player. All of the variables on players' ends vary way too much to really determine if it's a problem with the player's connection. Based on what you said, you clearly aren't using the modems that are known for causing these problems. I've even seen a few players recommend Netgear. A lot of these errors start showing up after certain updates for a lot of players, so something could be botched with the game right now.