I'm doing background prep for a neurology appointment next week. MG is on my list to ask about. I definitely have days where keeping my eyes open is more difficult than staying awake. E.g. I can be awake for hours concentrating on an audio book but not keep my eyes open. It does come with greater feeling of sleepiness than normal though. Mostly my ME fatigue has been tired but wired, so not sleepy.
I don't think I have MG instead of ME but it is something that sometimes coincides with autoimmune conditions, and there seems to be AchR issues with both POTS and ME.