Good info to get out there for new puppy owners.
I have Elroy's posts out right now and want to hold off on reposting since we're getting a rain mix and they've been staying solid pretty well. That doesn't mean I'm going to get complacent though.
Hoping you get lucky and they will stay solid without much more effort.
With my current girls one was finished a LOT faster than her sister. Same length crops and all of that but the one girl just seemed like she 'wanted' to perk her ears up more than the other. (like when you whistle at them or snap your fingers - how the ears will perk up)
The other was a nightmare and took an extra month of full on posting and then god only knows how many breath rite strips (multiple boxes worth) after that and that one ear in particular just kept on flopping over after a day or two.

She could definitely pick that ear up if I was whistling at her or waving a pig ear but otherwise she was perfectly happy having that one flopped over like a deflated balloon.
Eventually I gave up on the one girl and resolved to accept the fact that her one ear was just going to look stupid forever and I would have to live with it. Keep in mind this was a few
months after her sister was finished.
I can't pin down exactly what changed or what led to it but a good few weeks after I gave up I started noticing that her one 'goofy' ear was standing better and more often. A little more time passed and I noticed it was standing all the time.
For the life of me I can't come to any reasonable explanation for it other than she was just messing with me and trying to cause me stress.
Some of the best advice I believe I ever got from an ear crop Vet was about how I should try to get them excited (snapping fingers to get their attention, showing a treat to get their attention, etc.) to get them to 'work' their ears and about how I should be doing that as often as possible and as many different ways as possible. At the time he told me that I couldn't really understand how that could help anything. The ear either stands or it does not was all I really could wrap my head around then. Right?
I think Dystopia (the one with the flop ear that I gave up on) was the dog that helped me better understand what he was talking about. That girl could pick up both ears just fine if I was waving a couple of pig ears around or doing something else to otherwise get her 'excited' and tuned up. Otherwise if she was just laying around doing nothing she was going to flop that thing over forward while she was relaxing. Similar to how a Dobie can be standing there looking in one particular direction and hear a slight sound off to one side and while the head may remain focused in the same direction as before - the one ear on the side of the noise will turn like a little radar to orient better towards the direction of that sound.
Dobermans have amazing abilities in how they can move and 'work' their ears to localize on sounds. If we give give them more stimulus / reason to
want to work the ears when they are young it seems to me like that would help them better develop their control over those those ear movements.