[Complexicate]

If you still have the Brother printer, try disabling IPv6 on the Brother printer.

I remember this issue from a while back. Some update happened, and then wireless printing stopped working on some iOS devices. It happened to a colleague's macbook, and disabling IPv6 on the Brother printer fixed it for us. I can't remember where I found the initial advice, but here's someone else mentioning it: https://discussions.apple.com/thread/250584298

[mauvehaus]

Any sufficiently large discussion of software complexity will spawn a large sub-thread about printers.

Any sufficiently large discussion of printers will beget a number of ad-hoc support sub-threads.