I watched your vids Robert, and I'm not really sure it's the issue but it seems like he me might be freaking out due to seeing his reflection (thinking it's another Aro) on the glass, which is easier to see apparently when the lights are off. I have a Flagtail that fights his own reflection for about half of each day lol. But yeah in the case of a young Aro that gets scared easily it's a bigger issue, as you don't want Aro to flip out and hit their head on sides or lid, can lead to drop-eye etc.
I personally can think of 2 possible solutions to try as you wish, perhaps others could add more:
-- if possible adjust ambient/outside tank lighting to reduce in-tank reflection (or maybe try putting a small night light over the tank, you can get one that comes in blue/ moonlight affect).
--try covering the sides of tank: the closer this material adheres to the tank glass/acrylic (e.g. with paint or oyama sticker), the less reflection will be on inside tank walls. If you just hang a loose piece of cloth or something over the side there will be more reflection. Plastic future board works ok (but oyama sticker is better).
To be frank I'm in a similar frustrating situation but a little different with one of my Aros (Goldenhead Xback) -- if I turn down his tank lighting too much he freaks out (and not really because of reflection issue, he just doesn't like the dark). I'm hoping he'll grow out of this, but for now I have to keep the tank lighting on 24/7 (but cover the 3/4 of the lid with some dark plastic future board to at least reduce lighting in most of the tank, leaving 1/4 of the tank lit. He sometimes swims around the covered area, but mostly stays in the lighted area, even when sleeping. My other Aro (Purple Blue Base Xback) totally doesn't mind to be in the dark.
Finally. hopefully as your Aro gets bigger and more confident lighting issues will affect it less, same as I'm hoping with mine.