I understand this is a bug/miscommunication in the forum software.
I've seen it happen on other forums as well.Not always but always from the same users if I'm not mistaken. The fact you mentioned "uploaded from an iPad", triggered a memory. I believe it is somehow connected to iPad or iPhone.
Perhaps just the upload or perhaps the editing on that class of device?
That's correct, have had it happen using iPhone. The work around for me was to rotate and up load the shot . Until it posted correctly .......... However there is no pattern as in rotating CW, each time to get the correct orientation.
As said desk top best option.
Greg