What most likely happened is your inverter lost its connection to the internet. It needs that connection to send data to the Solarweb and PVOutput sites (and hence also needed for any apps that use those sites to display data).
There could be any one of a number of reasons why your inverter lost connection to the internet (and could not automatically reconnect).
If your inverter is connected via wifi to your router, then outages can and do happen and often the connection is not successfully or automatically re-established after such outages.
I used to have this problem with my Fronius Symo. I took a range of steps to aid it to automatically reconnect after outages (be they power outages, or internet or wifi/router outages):
I put my router (and NBN NTD) on a UPS power supply, so they will continue to provide internet connection during power outages (at least for as long as the UPS batter lasts, in my case 2 hours). This helped because after a short power outage, my NBN box and router either failed to or took too long to reestablish an internet connection (fixed wireless here) and by that stage the inverter’s data manager had given up trying as it had failed to reconnect during the time the internet was offline. My NBN NTD won’t reset correctly with short outages (it needs to be powered off for about 20 seconds before restarting to invoke a proper reset and reestablishment of internet connection).
I also assigned in both my wifi router and in the inverter a fixed IP address for my inverter. For some reason I found this also helped to improve the chances of a successful automatic reconnection after outages. Plenty have told me it shouldn’t matter, but it was my experience that it helped. I had exactly the same failure to auto reconnect issue with our Fetch TV set top boxes. Once I gave them a fixed IP address, they also auto reconnected after power outages. I don’t have this issue with many other devices though.
check the Inverter’s datamanager’s firmware and update it to the latest version if it’s not already. There was a period in the last year or so where some firmware versions had downgraded the wifi signal reception strength at the inverter (something to do with Euro standards), and the wifi connection to an externally mounted inverter can often be a bit flakey in the best conditions, less so with a firmware that deliberately degraded wifi signal reception. That issue was corrected in more recent firmware updates.
We get a lot of outages here, so I had ample opportunity to test out the solution which worked for us. I used to need to reboot the inverter a few times a week due to the issue of the inverter failure to reestablish an internet connection. Since I did the above I can’t recall the last time I needed to reboot.
Some people have hardwired an ethernet cable from the inverter to their router, and this generally provides for the most reliable connection. Others have set up a wifi repeater near their inverter to help provide a stronger wifi signal.
The OP showed images of their inverter display panel working just fine, producing power (one image shows it was outputting 1946W at that moment, the other image shows the output history chart for the day). Yet at same time the online systems were not operating, which means the issue is the connection between the inverter and the online systems.