You have to play with the aggression based matchmaking of the game.
It's been confirmed fully by devs and I guess it's here to stay.
If you do something like 10 raids in a row without shooting or dealing even 1 damage to another raider you will get placed in super chill lobbies where it's very uncommon to be shot at.
What is very frustrating but important to understand is that the game doesn't care who shot first. So if someone rats you at extract and you shoot back, your "aggression rating" will increase. The next game you are likely to be placed again with more PvP players. Again if you shoot back, it will get worse. It's a vicious circle toward more aggressive lobbies.
So my advice is simple, if you want chill lobbies, go to stella Montis for at least 7 to 10 raids and bring nothing in term of loadout. If someone shoots you, so be it. Run, flee hide, do whatever you can to avoid conflict. And if you die with nothing then it's ok. For that I highly advise not going with a free loadout but with a dirt cheap basic loadout with just a ferro to kill Arcs. That way at the very least you can safe pocket stuff even when players or Arcs kill you.
I call these "expiatory raids". I'm the punching bag of the server but eventually I will be with friendly raiders.
That aggression based matchmaking is particularly bad if you have an hybrid playstyle and play both PvP sessions and PvE sessions. Everytime you decide to change your play style towards other players it will take around 10 raids for the matchmaker to adjust.
I'm not religious but in this case :
If anyone slaps you on the right cheek, turn to them the other cheek also
That's the recipe to getting to chill lobbies.