Suppressors Got my Templar Archangel!!!

What suppressor covers are yall running? I got an Armageddon suppressor cover (Suppressor Cover - TBAC 30P1 and all 1.5" x 9" Suppressors) for my Archangel and have had pretty bad issues with mirage. 15-20 shot strings over 10-15 minutes made the sight picture horrible. It was particularly bad two weeks ago at a 1000yd club match where after 10-12 shots I had to back down my S&B 5-25x down to ~15x to not have the target shiver like a chihuahua in Antarctica.

Are yall having the same issues? If not, what're you doing to mitigate this?