As found by some user here: https://forum.armbian.com/topic/6033-helios4-support/?do=findComment&comment=111265
The LEDs on the Helios4 stopped working at Version 20.08.14. I confirmed they are not working on current 20.11-trunk. As we had some issue with the GPIO assignment for the FAN2 I assume it is a similar issue for the LEDs.
Depending on the release date of 20.11 this might need backporting to 20.08, as the LEDs are quite important.