Keep in mind that not all blu-ray players support AVCHD. So, make sure that yours does!
Edit: Also, you seem to keep using AVCHD and blu-ray interchangeably. Which is it that you’re trying to burn? A DVD9, or a BD25?
Well I’m currently trying to burn AVCHD on a standard DVD btw do all burners support duel layer burning (I actually need to get some DL dvds and try again, and my blu ray player is definitely able to play AVCHD, I checked 😊) other than that I’m stumped lol