Sidearm savant / Complete Night Raid using only pistol , knives or gadgets .
I did those dint get achievement , giving your squad to attack x enemies make's it not count ? redid it again on EZ 1 pistol shot on the execute squad , knife only no throwing knives,, no squad engage order used and rpg only for chopper still no achievement ...

I did the mission Night Raid only with a knife and the RPG 7 for the Heli
I got the weapon skin Polar Nexus but not the Sidearm Savant. Didn´t used the squad attacks
Also just with a Pistol and RPG 7 but the same result

Also not popping for me

Same for me!

Yeah mine did not work either. I will NOT be going back. I do not care enough about the crappy campaign rewards.

I found the solution and it worked for me so maybe you can complete the achievement too. Here's the quote:
https://forums.ea.com/idea/battlefield-6-bug-reports-en/sidearm-savant-achievement-will-not-unlock/12737839
"If you finish the mission doing the challenge, just wait until the start of the next mission lets you move, and then leave to main menu. Then go back to the campaign missions, hit continue on this mission, and it will replay the last cutscene and give you the achievement. It just worked for me, and seemingly others as well."

Can confirm the above method worked for me.

Well I did the same, got the Sidearm Savant, but did not get the Polar Nexus completion.....
Did the suggested fix, and it awarded the completion for the Polar Nexus.

I shot the primary at the ground at the start of the mission to test the recoil and what do you know, no achievement.

Above worked for me too, an friend which did the mission before completing the campaign got the achievement correctly after the last cutscene

I made a
quick guide
for anyone wanting to find the fix:
You can use the RPG, but only to take out the heli. You can use the throwing knives. You can order your squadmates to take down threats as you see fit.
The mission's bugged, but it's not hard to get the achievement - there is a workaround:
1) complete "Night Raid", making sure that you only use your knives, pistol and squad commands to eliminate threats;
2) after you take down the heli, a cutscene will start - let it play out;
3) you will get taken to the next mission, "No Sleep", watch the cutscene and wait until your character is off the helicopter;
4) once you're able to move, hit ESC and return to the menu;
5) from the menu, navigate to your campaign missions list and find "Night Raid";
6) continuing the mission will restart the cutscene from the end of "Night Raid" - let it finish;
7) once the cutscene with the car ends and the next one with Gecko in the house starts, you will be awarded with the achievement.
If by the end of it you still don't get the achievement, then you must've done something wrong during your playthrough, or there's something else wrong with the mission.

If you don't know why you didn't get "Sidearm Savant" or Polar Nexus Camo, most likely you equipped the knife and used it with the "fire" button.
When you equip your knife and use the "fire" button, the game thinks you are shooting and doesn't give you an achievement or challenge

If you don't know why you didn't get "Sidearm Savant" or Polar Nexus Camo, most likely you equipped the knife and used it with the "fire" button.
When you equip your knife and use the "fire" button, the game thinks you are shooting and doesn't give you an achievement or challenge
no ♥♥♥♥♥♥♥ way it says you can use knives? bro thats actually retarded

No kidding. I definitely messed with the knife as well. Got 0 achievements after only using the pistol and knife

If you don't know why you didn't get "Sidearm Savant" or Polar Nexus Camo, most likely you equipped the knife and used it with the "fire" button.
When you equip your knife and use the "fire" button, the game thinks you are shooting and doesn't give you an achievement or challenge
I wonder if that means it works like some of the older Battlefield games where the knife actually shoots a tiny projectile to deal damage.

If you don't know why you didn't get "Sidearm Savant" or Polar Nexus Camo, most likely you equipped the knife and used it with the "fire" button.
When you equip your knife and use the "fire" button, the game thinks you are shooting and doesn't give you an achievement or challenge
False , i only use knife with fire button and got the achievement , did a knife only playthrough