Host Migration/Lost Connection to the host -> kicked out

[Popii97]

Title says it all.
1. I select a mission, I'm waiting for players, the ships are flying: as the screen loads we're heading for the planet and boom the screen goes black for 2 seconds then the it comes back to normal but guess what? "Host Migration in progress please wait".
2. The other case is when I am actually finishing the mission and heading for extraction (which happens extremely rare) and then, from nowhere, I lose connection or "host migration in progress" . BAM! Back in the ship.
and
3. The third case is when I am playing the mission nice and smoothly and people are joining in to play and after a while they just disappear and i am alone, again . 

Can anyone tell me what is going on? and why? Because i can't find a reason. My internet is good , my PC is just fine for multiplayer games. 
I really love this game, but it's pretty hard to enjoy it if I'm just wandering in my ship or doing the missions solo.