Everything has suddenly gotten WAY harder

[(PSN)Cha0sReaperXL007]

So some usual buddies and I have been playing and grinding the game pretty strong the past couple months easily clearing kuva liches and hunting eidalons with relative ease and skill until last night. My Excalibur Umbra which I use frequently on Sedna defense missions and sorties with no problem suddenly started taking and dealing damage like I was an unranked Excalibur with starting weapons instead of my gear that ive used to topple high level enemies with ease on top of getting one shot through walls and cover. Today one of my friends who is a Rhino Prime main started having the same issues with not being able to deal damage or take a hit. Is anyone else dealing with similar issues like this?!