Reboot fails, unclear cause.

Hello. My q670 8-bay white motherboard (store url was https://cwwk.net/products/q670-8bay-nas-mini-itx-motherboard-upgrade-version-lga1700-supports-intel-12-14-generation-processors-8sata-4m-2-ddr5-dual-slots-5x-usb3-2-8-sata3-0-ports-i226lm-2-5g-with-vpro , it seems to be discontinued) seems to no longer reboot properly. From UEFI screen, when choosing "save and restart", the PSU sounds like the computer is rebooting but there is no beep or POST screen. This happens with only keyboard, HDMI, CPU fan and power connected to board. It also happens when giving reboot command from Linux OS. I do not know how to troubleshoot further, advice would be appreciated. 

Workaround has been physical power off - power on at wall outlet (card is set to boot on power). Reset is desirable for remote control of server.