Here's the link to the Evernote ScanSnap Software
https://www.linksdriver.com/2019/12/fujitsu-scansnap-evernote-software.html
Note that in my case, I finally realized that it stopped working because my firewall's wifi was upgraded from 2.4 GHz to 5GHz (had the same problem with an older printer). If I run it on the 2.4 band it worked fine after I just reinstalled the scansnap manager software from the above link. I did not go through the firmware update process as I ran into the same issue as you did.
This should be a lot easier to find out about....