2012 Kawasaki Ninja 650 Popping on high revs?

Hello everyone I need some help trying to figure out what could be going on. I have a 2012 Kawasaki Ninja 650 with only ~11,000 miles on it. I recently have flashed my ECU with two wheel dyno works. The only modifications to the bike are:

1. Twin Brothers Exhaust
2. Flashed ECU
3. K&N Air filter

Obviously when I got it back there was a check engine light which is normal I believe when you flash the ECU. I capped the AIS system and put everything back together. Heres the problem: When I try to go past 4,000 RPMS on the 5th or 6th gear theres a lot of pops coming from the exhaust and I lose power. The engine doesn't die but it does have trouble accelerating until I drop gears and rev it. I put the bike in neutral and revved the bike to 7,000 RPMs with no problem. I am not sure what is happening?

I removed the gas and put new 91 octane fuel in it to make sure that it wasn't bad gas. I took off the tank to make sure that the line wasn't kinked. I cleaned the air filter and put it back. The same issue is still occurring. What could it be? (Also showing error code 32)