Hi there!
You likely should keep posting longer than five months. You should post until all his adult teeth are in. Even at that point, assess things objectively and make a decision.
What I see in your pictures is that when the ears are down, they are being held down – similar to the "airplane ears" position; but it does not look (in that pic, anyway), like ears that are flopped.
But better to play it safe than to lose progress. I know we want to stop posting as soon as possible, as it gets old! I know I'm that way at least. What's more, with my Dobes thus far, I have run into some troubles as time went on in terms of irritation that made it even more troublesome; so being done posting was so tantalizing. With Oji, here, it worked out that as I was having trouble with irritation down in the ears which was resulting in a clear moisture buildup, I stopped posting and thank God it turned out he was good to go.