Rifle Scopes Complicated Burris Eliminater

Lengthily question but I am completely baffled. I started years ago with a Burriss Eliminater 3 scope and fell in love with the accuracy of it. I then put a Burris4 on my 22-250 and had very good results on prairie dog shoots. The last day of our last hunt the scope quit. Just quit. I sent it in to Burris and they said it was unrepareable and sent me a Eliminater 5 to replace it. Here’s where all of the questions start. I put the 5 on the same rifle and had to put the number two shim under it to elevate to zero@100 yards. Never had a shim under the previous Burris. Never could get the rifle to hold a group. This is the same rifle that was splattering dogs at 400. I sent it back for something being wrong and they sent me another 5. This scope needed a number 3 shim to zero @ 100. Will not group. Has Burris gone down hill? Customer Service huffed and puffed but they did try. What’s the thoughts on this. Going from no spacers and working like a dream on the Eliminater 3 to having to shim up to number 3 shim and not holding a pattern.