Getting blocks during phone calls is very common and happens to me all the time. We can't imply words or use gestures to insinuate what we're saying like we can in-person. If you get a block in front of someone, they'll notice you're stuttering, but on the phone it's just silence and they have no idea. So there's a lot of pressure on the phone, conscious or subconscious. Phone calls are big challenges for me, depending on what they're for. And God forbid they ask my full name or phone number 🙃