Microphone is not working perfectly when on Loudspeaker
I recently had to change my iphone xs charging flex. Problem occurred after that. Everything is working fine except low microphone sound while on speaker. Other party can hear me clearly when i am using ear speaker (not loudpseaker/speakerphone). Problem occurs only when i switch to loudspeaker/speaker. Other party starts to hear too low sound. When i switch to ear speaker, other party starts to hear perfectly. i have tried recording using voice memo app, front camera video, back camera video, everything works fine. Only other party hears too low sound when i am on loudspeaker/speakerphone on phone or any other apps calls.
What's the problem and how to solve it?
Thanks
iPhone 6s, iOS 15