Once I have uploaded an image, and if I find it is bigger than I wanted, I can't load a smaller one. I delete the picture from the post, I delete the file from the uploads (Just to be sure I'm not reloading the original), I resize the image to make it smaller, I re-upload it, then when I send to editor I get the original big picture. I can do this ten times with no change. I have saved the post and started over re-editing it, and I have tried different setting, i.e. link to page or link to file (which I don't understand their purposes), but still I get the old file.
In the past I have even gotten other pictures entirely - I would send to editor and get a picture I had sent to editor before.
This is multiplying the time I spend composing a post by at least ten or twenty fold.