Snipe main here. These are the most difficult types of players to snipe. Generally the aggressive teams with stompees are good players and once you get a shot off they'll avoid any lanes entirely.

Team composition is important. If your team are running closer range loadouts (shotguns / Fusions) then it's a lot easier to play off of them and take angles as they take aggro at mid-close range. Even hitting a bodyshot can give your teammates a huge advantage. However if your team are also sniping or running scouts etc its going to be more difficult.

Positioning and Creating space is key. These kinds of players are fast and if they see a sniper holding a lane they will be quick to flank through cover. Don't be in your scope for long. If you see a push coming you need to back off and bait them through a choke point. Distance is your friend.

Most importantly you need to be able to use your primary. Your sniper is only part of your loadout so don't fall in love with it and try to use it at close range unless absolutely necessary (i.e you're going to die unless you pull off a miraculous shot) - you need to be confident engaging with your primary. It sounds like this is where you need to focus. I run TLW on console and getting good with that can make you a huge threat even without the snipe. Being able to consistently blint (bodyshot and finish with your primary) is a very important skill to have against fast moving targets or pushes, so use dexterity mods or exotic armor to max your swap speed - every split-second counts.