iPhone 13 Pro Call Issues

I recently upgraded from an iPhone 8 Plus to an iPhone 13 Pro and ever since then I am having call quality issues where the person on the other line cannot hear me intermittently during the phone call - this seems to happen when I have my phone on speaker or connected via Bluetooth. I have never had these issues and I am still living and traveling in the same area and have the same wireless provider, so I am at a loss as to why this newer phone has such poor call quality.