This is probably not directly linked to OMV, but as there are many wise people here maybe someone can help or has experienced the same 
My system/power LED-indicator used to blink in OMV3 when the NAS entered suspend-mode (Autoshutdown plugin: pm-suspend). After upgrading to OMV4, this does no longer happen (I only recently upgraded). The LED is constantly on, and this is off course very annoying as I'm having problems identifying whether the NAS is on or not. As far as my googling goes, this is not software related, but something that is set in BIOS. However, as stated, it did work in OMV3, so there must have been a change somewhere. I have tried looking through the BIOS, and I cannot not find anything. I also updated to latest BIOS without success. My motherboard is a Supermicro X9SCM-F.
Anyone having any tips how to get the blinking back? I'm very close to keep my NAS on 24/7 just to avvoid this........ 