1.4 and later - No automatic (delayed) updates on Oreo, Pie or 10

• Device OS and version: Huawei w/ non-stock OmniROM 8.1.0 / 9
• F-Droid version (in the About screen): 1.4 / 1.5 / 1.6-alpha0
• F-Droid privileged extension version (if installed): Nope

What did you do? (clear steps if possible)

• Enabled update check every 12h (or even 1h)
• Download sliders to the right
• Disabled battery optimizations for F-Droid
• Kept F-Droid as open app
• Also went through multiple network changes (Wi-Fi<>mobile)

(sorry for not-English but as you know changing locale will trigger an update)

What did you expect to see?

• Index auto-updates every 12h (or even 1h)

What did you see instead?

• No index update since my last manual one (Oct. 19, 11:56am)
• No (obvious) errors in the logs
• I can un/install apps just fine

Note:

• I usually just OCD pull to refresh so I don't know if on stock ROM this was a thing.
• I have one Android 6.0.1 device that had updated, so this must be somehow specific to my setup.
• In the past changing the network would trigger update checks (rather annoyingly even)

I'll be careful to not "pull-to-refresh" by mistake, but I need some guidance on how to proceed.