iPhone SE mic and other issues

I have an iphone SE that I am having issues with that I hope someone can help me with. It was brought to me to try and fix. First of all, the ear speaker will not work at all, it will not switch over to headphone mode when you plug in headphones. Siri will not pick up your voice, when you open voice memos, the record and play buttons are grayed out and you cannot select them. Also, during a phone call you can't switch it over to speakerphone because the buttons are grayed out too. However, the speaker does work to play music or videos and system sounds. I've replaced both the front camera flex cable and the charge port flex cable with the same results. Do you suppose that There are motherboard issues or is it another part of the phone that I'm overlooking?

Thanks for the assistance.