It is normal to experience a few hard shifts and funny shifting patterns for the first 200km after installing the tunes, this is just the time it takes for the transmission to complete the relearn process.
It is especially normal for this jerk to occur when shifting into reverse, because when you put it in reverse, your line pressure is doubled.
During the relearn process, we recommend that you drive in stop-and-go traffic if possible, and also have conservative throttle input.
If the odd shifting patterns ever persisted, we recommend that you try re-flashing the tunes onto the truck so it can restart the relearn process. However, if after that second relearn process it was still not to your satisfaction, we could always reach out to the tuning company and request a tune revision for the TCM tuning.