Sony now reports that the A1 firmware update has been suspended:
It was confirmed that some products updated to Ver.2.00 may not be able to connect to the network.
Due to this issue, we have suspended the update. (March 29, 2024)
Yesterday one of my readers shared this screenshot showing the problem on the A7sIII too:
Hope Sony can fix this ASAP because now A1 users will have quite an annoying issue!