[RoIIouT]

Apologies if this has been address before (I could not find anything).
I have a 2016 340i xdrive with a catless VRSF and Bm3 Stg 2 93.

Everything was running very good until I changed my spark plugs last Saturday. I am running NGK 94201 gapped to 0.022' - 0.023'.

Occasionally, when I am rolling on the throttle in about 2nd gear around ~5k RPM I get a sudden loss of power and hear very loud backfire from the downpipe area. This is extremely hard to reproduce as I have not found a consistent way to make it happen. I'm hoping maybe it has something to do with the tune and it's not a larger issue. I haven't tried flashing back to stock, but I may do that later this week and drive on it for sometime to see if the issue is resolved.
If it's the sparkplugs, why the hell would my car be running worse on (technically) better plugs?

Also, sometimes when pulling the car feels hesitant and jerky, but I'm think this could be related to putting on fresh snow tires? I don't really notice any rpm drop like in the other issue.

I appreciate any input.
Thanks.