airport time machine os 13.0, airport utility config issue

The Time Capsule is a "network" drive that is designed to connect to a modem or router using an Ethernet connection. Your Mac Mini is not a modem or router, so in your current setup (no modem or Wi-Fi router), the Time Capsule cannot be configured as it was designed and AirPort Utility is complaining.

Another way to say the same thing......you are now trying to use the Time Capsule as if it were a USB drive connected directly to your Mac Mini. But, the Time Capsule is not designed to work this way.

Frankly, I don't understand why you are able to back up to the Time Capsule unless you are turning off the Wi-Fi connection on your Mac first, backing up, then turning the Wi-Fi connection back on.

But, if things are working OK now for backups, I would not worry about the settings in AirPort Utility, since they are expecting the Time Capsule to be connected directly to a modem, or another router.

Whether your computer connects to the Time Capsule using Wi-Fi or Ethernet, the Time Capsule still has to be connected to a modem or another router via a wired Ethernet connection.

So, the signal path (the way that the Time Capsule is designed) to your computer is......

Internet > Modem (or another router) > Time Capsule > Your Mac ( connected either by Ethernet or Wi-Fi).

Tell us more about the "community Wi-Fi". Has your community furnished you with a modem or router that provides your Wi-Fi service?

If they have, the Time Capsule needs to connect to that device using an Ethernet cable, and then you can connect your computer to the Time Capsule using another separate Ethernet cable....if you desire a wired connection between your computer and the Time Capsule.

For some reason, the last paragraph was not included in my reply. Here it is.....

If you are saying that you do have a modem or router that has been provided for your community Wi-Fi....and....the network has been set up as follows.......

modem (router) > wired Ethernet connection to the Time Capsule > wired Ethernet connection to the computer, then we can look at changing some settings using AirPort Utility to stop the application from complaining.

Unfortunately, I don't have anywhere near the type of connection that you do, so I cannot duplicate your setup to test.

I also do not have a Mac running OS13......which is likely the culprit here......but cannot test that out.

Perhaps another user can help.

Thanks, I understood the concept perfectly before your detailed description.

But, I can't set up the same type of network here to test things out on the same type of network configuration without completely destroying my current setup for at least a day, maybe more.

Even if wanted to do this, I can't test things with a Mac running OS 13.....which, as I mentioned is likely the culprit, since you indicate that you had no problems with this prior to installing OS 13.

A guess would an issue with Internet Sharing on the OS 13 Mac. If you have not already done so, try removing the Internet Sharing settings and restart the Mac. Then, set up Internet Sharing again on the Mac.

After all.......what changed? Things were fine when you were using OS 12 and the issue surfaced with OS 13. Apple will probably have another 3-4 updates for the system in the next month or so, perhaps with a fix.

Hopefully another user who has installed OS 13.0 or 13.1 can help, since that appears to be the culprit here.