

Not that I’m an expert, but I could have sworn I’ve seen people in the past who were talking about accidentally messing with the physical stuff involved with the headphone jack when they hard drive swapped.
I might be misremembering but just wanted to suggest that you may want to check into whether it could be physical, and not software related, because if you’re troubleshooting the wrong cause you can get stuck on it for quite a while.
Yay! Glad to hear that you found the solution!