26.1 is out!!!

[OPNenthu]

I can't :(

Ever since I made manual changes to my network layout in NetworkManager, IF up/down commands doesn't have any effect on the bridges.
The only thing that works to clear the network stack is to reboot.

Are you sure : https://man.archlinux.org/man/nmcli.1.en ?!

And if you are running any Desktop Environment on that 'Desktop Client' you should be able to do it with a single click :)

If both things don't work it's time to submit a bug to the NetworkManager developers IMHO...

Just FF tabs open at that point.

Then there is a chance that Firefox was holding onto the IP stack so to speak and preventing it to recover properly.

At least that's my experience with both the Linux and Windows version.

I'll play around some more with the nmcli commands when I get a moment but as for reporting bugs upstream... sigh.  This is the downside of Linux and why I wish FreeBSD was on par as a desktop OS.  Linux is made up of thousands of independent packages and as a user I would need to open accounts and track bugs all over the damn place.  That's not likely to happen if I'm honest.

As a developer of a package or a kernel contributor it's perfectly fine, but as an end user of a distribution it's kind of maddening at times.  On the plus side, I've found very little that doesn't work on my particular hardware.

At least OPNsense is easy to contribute / report to. :)

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UPDATE: to close the loop, I was able to bring the bridge interface down with 'nmcli conn down br0', but the inverse 'nmcli conn up br0' returned success and never actually brought it up.  I followed up with 'nmcli device up br0' and this timed out (failed).  I then used the GUI toggle switch for the parent interface (which was already up in 'ip a' but showed as down in the GUI) and it brought it back up.  However the same toggle switch does not bring the br0 interface down :P

So it's quite an inconsistent mess.  Probably either a Mint / Ubuntu bug, or my configuration is just too complex or I set it up incorrectly.