I struggle with phonecalls because I struggle with unscripted conversations. It takes me a long time to formulate some verbal responses, and this is met with the other person getting frustrated, or trying to siphon in more questions when I'm thinking of responses to the first thing they've asked.
I've also been called a robot more times than I can count. I've been asked if I'm a real person or one of those IVR AI systems.
I have actually worked in call centres, and for the most part, been able to script my responses ahead of time because there are only so many things people call in for, so it's easy for me to revert back to some sort of script, even if it's one I've made myself for that situation.
However, if my phone rings and I don't know who is calling, why they're calling, it can send me into a meltdown, a real neurological distress response to an overwhelming situation. This is what my manager could not understand about how I could work happily, productively, and perform better than anyone else in my team, but could not answer random teams phone calls that weren't in my calendar for the day, with no prior warning or notice.
I am diagnosed autistic, and late diagnosed too, so all my life I have been struggling with these phone calls and people telling me I'm simply using anxiety as an excuse.
Frankly I think we live in a world now where there should be more options for communication, rather than just phone calls. It would be more accessible, and make for better workplace, healthcare and administrative purposes.