"Suddenly my reloads are going POOF."
How often? 1 in 5? 1 in 10? 1 in 25?
The reason is not enough powder burn. Why?
You can speculate and switch things at random and maybe stumble on the answer, or maybe the problem will just go away. But if you want to KNOW, the only way to find out is to dissect enough loaded rounds to be certain you would have included a poofer.
I would could open a shell, dump the shot, pull the wad with needlenose pliers and examine it for having been cocked or a nicked powder skirt. I'd weigh the powder charge and record the value. I'd pick up another round and repeat until I found a mechanical flaw. All I'd have paid for that information would be 30 minutes of my time and a couple handsfull of hulls. But I'd either know what was causing the poofer or at least know that I had examined everything I could test for.
If the drops are consistent and the wads OK, all that's left in the equation is the primer; change it.
I've wrestled with 2 tricky light powder drop instances. The first turned out to be insufficient charge bar travel; just enough to drop 1 in 10 light. The second was with E3 powder and powder baffles. I never understood exactly why, but having 2 different styles of baffle to try, as well as no baffle at all, I determined that the only way to avoid 1 bad drop in 1,000 was with no baffle at all.