Crash on startup on iPhone 5S (only)

For some reason my packaged game works fine in all iPhone/iPad platforms I tested (6S, 7+, X, Air2) but it crashes on startup on the 5S. In that particular device it stays on the splash screen for a long time and then eventually crashes.

Interestingly, the option to cook textures for A7 chip is enabled. I don’t know what else on the 5S makes it unsuitable for my app - in the past it used to run, slowly but not crashing.

Does anyone know what could be causing this issue on that platform alone while working in all others?

On a related question - I couldn’t find a way to remove support for a certain Apple device. That’s probably too late now since I can’t officially remove support to a device as per Apple rules, but would be interested to learn for future apps.