Nah I'm exactly the same with reading alongside somebody. I'm not 100% fluent with singing alone - but again, I'm fine if I'm singing along with with a song or another person. The inconsistency is SUPER annoying. I've kept journals about it when I was younger before. Like, trying to pinpoint if it was sleep, food, booze, hormones etc etc that was somehow causing fluctuations. But I never saw any correlation. My stuttering just seems totally random. When you have those bad days and you don't know what the heck is going on and what's causing it, man, pisses me off so bad. Haha!