Bangle 2 HRM problem

No matter what time I select for the backlight to stay on, I always goes off after roughly 5 seconds.

Try Settings Utils Rewrite Settings - that should fix it for you.

It was an issue that could happen with earlier firmwares. Installing 2v11 will stop it from re-occurring, but once you have had it happen you need to do Rewrite Settings (or just reinstall everything) to fix it