Why cant others hear me during phone calls?

A few months ago, I was working outside and there was a pretty bad downpour and I got soaked. Phone was in my pocket and the phone started to think headphones were plugged in when they were not. Did some reading and water getting in the headphone jack seemed to be the common reason. So into rice the phone went for 2 days and it seemed fine afterwards. However since then, gradually it has been more and more difficult for people on the other end of the phone to hear me. Its at the point where they barely hear me at all, I cut in and out. However if I put in a set of headphones to use to talk through, they hear me clear as can be.

Is it likely that I should be trying to replace the speaker on the bottom of the phone, which appears to be a shared part with the headphone port and lightning connector? Just trying to double check whats recommended before ordering any parts.

Also, I had done a factory reset a couple months ago (after the possible water incident) since the phone was randomly shutting off. That issue was resolved. Just wanted to mention it since when I did a brief search on the issue I saw it was recommended to try a restore. So I have recently done that.