Your title mentions high pressure situations, but you probably would say that "hey siri" and greeting relatives aren't particularly high pressure. It sounds like its the initiation of speech that's troubling for you regardless of whether its a high pressure situation or not, but high pressure situations clearly don't help. Does stuttering feel like something that just "happens" to you? Because that would be similar to my experience too. There really is so much to say about this and the underlying causes at play but yeah I just want to say that I feel your pain broski. Have a look at my recent posts and it might provide some helpful information.