This would seem to be an iOS issue dealing with the specific encoding Arlo uses. Try using the free VLC viewer to share but for editing I suspect you may need yet another editor.
Maybe you need to look on an IPhone 8
Well, I don't have one. I posted my results in hopes that they would help pin down what the problem is (and isn't). So I guess we know it's not iOS itself.
BTW, I don't work for Arlo, and I have no idea what devices they use for testing.
guess someone was doing something about this, just didn’t want to let us know. Nice.
Good news. FWIW, I'm thinking Apple fixed it. I reproduced this with other videos that weren' from Arlo, so I don't think it was their bug.