network issues across Sequoia and ventura.

My home network is wired as well as wifi. I prefer to use ethernet, but the problems described occur in the same way no matter how I am connected, ethernet or wifi.

The home base is an iMac 5k 27" 2017 running Ventura 13.7.5. The satellite computers are both running Sequoia 15.4.1. They are a Mac Mini 2018 and a MacBook Air M1.

After upgrading to Ventura 13.7.5 and 15.4 I started having issues across the network. All computers can get internet fine, all have had diagnostics run and that is fine, no issues. I have run first aid on all disks internal and external, no problems. I reset SMC.

Everything native runs fine—ie, when working on a single machine not on the network, including search and internet.

If I join the network from the home base desktop to the M1 or the Mac Mini , no problems. IOW, if I join the network FROM the base to the satellites, there is NO network issue, no search issue, so the ventura machine can join Sequoia_s, but Sequoia machines cannot join Ventura machine.

It is when I attempt to "join" the network from the Mac Mini or from the M1 that issues arise, ie Sequoia joining ventura.

If I try to get onto the network from the M1, I get the indication on the finder window saying "connecting," but it never connects. Entering the password for the network makes no difference.

Weirdly, on the Mac Mini, the same thing—the "connecting" finder window— happens, BUT I can see and access my home based external drives in the finder icon of the dock, so I can access them even though the network finder window continues to display "connecting."

If I open the external drive on the mini from the finder icon in the dock, a drive physically connected to the home base, I can access the files from the mini, but the finder search does not work at all. I look for kingarthur.jpg and nothing (or one or two) comes up, it just says "searching." This happens even when I know there are hundreds of file names that contain the string "kingarthur."

Safe mode on the mini same issue.

I could not enter safe mode for some reason on the M1—likely another issue?

When Sequoia was 15.4 I attempted a reinstall of the operating systems on all three computers; 13.7.5 on the home base—successful, 15.4 on the Mac Mini—successful, and 15.4 on the M1—unsuccessful after partial install at around the 2h30m mark.

After the reinstalls— the successful ones, 13.7.5 and 15.4— the network behaved properly on all machines and the search function worked properly. I thought I was cured. And I thought it pointed to 13.7.5 as the culprit.

Then 15.4.1 came out with security and "bug fixes" and "recommended for all users." I installed it on both the Mini and the M1—successful this time. However, thereafter the network problems reappeared just as before and reinstalling the OS_s did not resolve the issue as it had before.

Any advice appreciated. I've probably run other tests, but just can't think of them now. I think this is a bug in the OS, but which one?

This is a network that has worked perfectly for a few years, ie prior to 15.4 and 13.7.5.

TIA