Possible EFI issue with Hawk DLX

[Pharaoh]

I have a 2020 Hawk DLX 250 EFI, and I'm trying to get to the bottom of what is wrong with it. During a road trip headed to my location was uneventful, however on the way back my engine completely shut off. The only thing I remember doing is just filling up with premium, and allowing my friend to put 1/3 Castrol ATF in the oil chamber during a oil change. During the shut off all of the lights and dash were still on and active, even though it would not restart. After waiting about 5 minutes or so it restarted, but after putting it in first gear and hitting the throttle at a certain RPMs it would shut back off. I had to abandon my bike and find a ride home, because I couldn't get no more than 20 meters at a time before it shut off again. After I finally got it home via towing I changed the oil, and clean the throttle body thinking that it was the carb immediately. Once I got it started again it idled just fine. It also went into first gear with no issue it would ride in first gear unless I would rise above a certain RPMs and then it would shut off again. Take into consideration, that if I switch gears before that RPM, I could make it all the way to 5th gear to get enough speed to make it to the store that was 1.5 miles away from my house. I did this repeatedly until it started back shutting off in first gear it seemed like with any RPMs. I was unable to gear up for a decent ride at all no switch gears at low RPMs or anything. After trying to troubleshoot it with a neighbor who was uneducated it stopped starting completely and I had bought a new spark plug. Afterwards I found cords unplugged that fueled the spark plug, I plugged them back up but I still can't get it to start. I get too fast cranks and then it's like the battery dies out, so I believe trying to start it on a low battery so many times may have messed up the battery. I kind of believe with a good battery I could achieve a start again, however I need to tackle the problem of it shutting off after a certain RPMs. So I need to figure out if it's still could be a bad battery or the computer system. It could also possibly be the throttle body, valve need to be adjusted, piston rings being bad, airbox, or even the fuel injection valves being clogged. When it cuts off it pretty much sputters like it's being choked out and then it shuts off. So I was wondering if it was that something is clogged. I am desperate to get to the bottom of this problem because I really enjoyed riding, and I love the freedom and feel of riding. So please can anybody help me find some answers in diagnostics, troubleshooting, or ways to fix the problem. Sorry that the post is so long and big thanks to anybody who will help!

[Pharaoh]

I am only looking for the reasons on why it's sputters and then cut off at certain RPMs, and/or also why it's not starting at all right now. I'm curious on the answers on how to get it back started and/or running properly. So cast your votes and give your reasoning and solutions if possible please and thank you so much for all of your time and help.