Dropbox app on Window 11 unable to connect to Internet, does not retain autostart or proxy setting

I just downloaded and installed the Dropbox app to my Win 11 Pro system, but it is unable to connect to the Internet.  I saw that some people were able to resolve this issue by turning off their proxy settings, so I tried that, quit the app, and restarted it, but the setting change I made does not stick.  The app reverts to "auto-detect" every time I restart it.  Incidentally, I also unchecked the box for autostarting with the computer, but that box also reverts to its default checked state ever time I quit the app and restart it.  (The setting changes are retained until I tell the app to quit--I checked that.)  Proxy is off in my OS settings, and automatically detect proxies is also off in my OS settings.  I have also tested the app on different wifi networks, some without firewall blocking, the native firewall is off on the computers I've used, and I have tested the app on systems with different antivirus apps, but I get the same result on every installation, every computer, every network, so I don't think it's a problem with firewall or wifi settings.