2021 Defender HD8 tuning

Hi guys, I am having a frustrating issue tuning my HD8 after upgrading to MRRPM gen2 trail cam, maverick heads and 840 BBK. From around 3000-4000rpm at light throttle, it often bucks and bogs down, and then sounds like a lean backfire. this happens often and is cyclic at times, and seems to be rpm-dependent. After 4-4500rpm, it runs smooth, and i have not had any issues at idle. I have checked fuel pressure with a gauge and reports about 47-48psi during these events without any dips. I upgraded the ignition coil hoping it would fix the issue, but no luck. During these backfires, my wideband shoots to 1.23 momentarily, which is max lean reading. VE tuning has been dialed in at this range. i was thinking the "Torque to Load" table needed to be modified, and i have tried some changes, without much success. I have included a log of these backfire events, and my current tune. Any ideas? I would appreciate any help i can get