2018 YZ250F Tranny Problem?

I need some advice please help!!!

I'm just going to give the full story to see if anyone can spot it out somewhere in there.

Couple of weeks ago i started to feel my "clutch slip" it siked me out but it would only happen occasionally so i left it alone. Last weekend was race day(did a full race prep on the bike oil/oil filter change, air filter change, adjusted the chain blah blah blah) I go for practice and hear my bike making that noise when your chain is too tight. Checked her out and she was fine. Still continued to make that sound, so i said f it and raced ending winning incase you wanted to know lol. Came home and did further investigation on the noise, turns out I legit only had 7 teeth on my 50 tooth sprocket(Sunstar brand "stock") So I bought a new sprocket and chain. Installed it and the next day I went riding. Bike felt great no problems what so ever.... Then today happened, I did a sight lap and she was fine, and on the next lap I went to start my moto. First few corners were great then I hit a hill and it kicked out of gear. Kept riding to see if itd go away and it kept doing it and doing it. So i figured my clutch was bad. Went to the truck took the cover off and didn't see anything chewed up or scarred. Let it cool down and tried it out again. 1st and 2nd are fine came out of the corner in 2nd shifted to 3rd hit a little jump and when I landed she almost threw me over the bars, like a false neutral. She'll shift through all the gears fine I guess it's just when I put power to 3rd gear I don't know.

I'm just trying to get an idea because everyone i ask has no clue. Bike has 20.1 hours to be exact. I bought a brand new bike to hopefully get the issues out of the way for a long time. I change the oil every 2-3 rides with a filter. Haven't noticed any metal shavings but today after it did this mess I drained the oil and found it to be sparkly, but no chunks of metal.

I can't play the game of "oh lets try this part, oh that didn't fix it lets try this part" I don't have the money. But any information from you guys would help setting me up in the ball park. Thank you.