Notifications by LED blinking not working

I see that K-9 mail is no more capable to notify new incoming mail by LED blinking.
Moreover, I can’t find anywhere the settings related to this notification feature (e.g. the LED colour associated to a specific account).
I noticed that this behaviour started since last June (maybe with v5.735/v5.736?), when the code for managing the notifications changed (completely?) to lean on the general android notifications system. Before then, the notifications by LED blinking had always worked as expected, and I was able to find and select the colour the notification LED in the K-9 mail settings.

Such an issue occurs to both me and my son on two distinct but identical devices:
Honor 9 lite (LLD-L31) - EMUI 9.1.0 - Android 9

Is this lack of LED blink notification a removed feature? If so, I would kindly ask the developers to consider reintroducing it ASAP.

Otherwise, I kindly ask for help for solving such issue.

Thank you.

K-9 blinks just fine on my OP3 and did so in A9, 10 and 11 (I’ve been testing quite a few roms on that old device in the last 2 weeks).

Go to any of your accounts - Settings - Notifications, then tap on Messages. That takes you to your device specific notification settings, or you can get there via your device Settings - Apps & Notifications, all apps, then K-9.

Under Advanced there is the LED on/off, color + duration you can set - but that also depends on the rom itself, I’m pretty sure I used one where I couldn’t select a color.

Thank you for your response, Nimueh.

Yes, I can easily reach that settings page and manage various notification options (for example, the notification ringtone associated to each account).
Unfortunately, I cannot find any “Advanced” sub-menu in the K-9 app specific notification settings with the mentioned options for LED on/off, color and duration.

All this make me think that there is a compatibility problem between my (stock) rom and the way the K-9 notifications are now managed (through the android notifications system).
Before the introduction of such changes in the code, everything was working fine on all my devices.
It’s a pity…

Considering that I really need the notification by LED blinking feature, probably I’ll have to revert back to a previous version of K-9.