HA Green not connecting anylonger

Hi, I am using HA GReen since July. I immediately connected it to an external SSD drive to get more storage. I move everything there and it worked super nicely. I create daily back-ups of my system on that drive as well as copy them to Google drive to be sure.
I am always latest versions of everything also my integrations. Last time an update was done was two days ago. All worked nicely and still this morning I did not have any issues. Until an hour ago: one of my integrations did not show correctly anylonger in my UI. As I couldn’t fix it I tried to reboot HA Green through the UI as I usually do. The restart button was there but when I pushed it I did not get the dialogue box I was used to telling me the system was restarting. Nothing happened at all. And also some options had disappeared from the list: I only had ‘Restart’ or ‘Restart in Safe mode’ but neither of the two worked.
I then manually restarted HA Green by pushing the button for 6 seconds. This worked and after restart the LEDs were flashing as they shoud (white continuously, green every second or so, yellow as a heartbeat). But still not able to connect anylonger. Getting the message in Safari (and other browsers) that HA cannot connect to the server. In the companion app on ipad and iphone getting the message: NSURLErrorDomain-1004 (cannot connect to server).
I also tried to ping my HA Green directly on 192.168.1.25 and that worked without a problem. I tried to connect it directly to my MacBook with an Ethernet cable but same issue.
I cannot connect anylonger and do not know what to do anymore. And no, I’m not using Alexa as a media player as I have read this could cause the issue. Thing is I do the updates manually and not automatically. I want to know which updates I’m installing and read the impact first prior to installing to be sure.
But I am out of options here.
Thanks for any help