I am hoping this post will help someone else. I'm not searching for help for myself anymore.
Since installing a new Orbi system about a week or so ago, I have had persistent but intermittent problems connecting to the scanner on our Brother MFC-9130CW multi-function printer. The printer portion works fine, and all of the other 20 or so connected devices also work as expected. Only the scanner has been unreliable. It would be available sometimes, perhaps half the time, and completely unaddressable at other times. Restarting the printer often worked to get a connection, but not always. The scanner had worked 100% reliably with the Apple Airport Extreme that the Orbi replaced, so it seemed like the new Orbi must be the culprit.
No adjustment to the router settings seemed to matter. Because the Orbi was functioning very well with everything else and because I was frustrated to the point of sending the Orbi back and trying something else, I began to consider the other components of my environment. To cut to the outcome, yesterday I found the latest firmware update for the Brother printer/scanner. After getting it installed, the scanner becaume 100% reliable once again. I have had no more connection failures at all since then.
The lesson for me is that a new component in this case actually might not be (was not) the source of a new problem. Perhaps the Orbi exposed an issue that the Airport Extreme was papering over? In this case, the printer/scanner was the culprit, and the firmware update brought up to speed on the new network.
