not always happy with GMC

Does anyone have an answer for this? My boss got a new 2023 GMC Sierra and it would happen occasionally when I would call him. I couldn't carry on a conversation with him because of hearing myself. It was extremely irritating. Well, now I have his truck and people are telling me that it occasionally does that to them. It doesn't happen all of the time. He used an iPhone, I use an android. I never had this happen in my 2016 or 2014 Sierra, except for when I was talking to my boss in this particular 2023 Sierra. I don't keep my phone in the cup holder.