Just passing on a tip that will hopefully save someone a few frustrating hours.

I moved a sub from one room to another with an Amp.  The iOSApp did the move perfectly.  Music worked initially but then dropped.  Performing a factory reset a couple of times would bring the sub back each time but would then drop minutes later.  Initially the eero 6 unit was next to the sub and another article said 1m separation was needed.  That was not the issue.

The root cause was too much distance between the sub and the Amp that were paired/coupled.  I switched the sub to a wired port on the eero unit and also connected the Amp to a wired connection.  Works perfectly now.  Not sure what the maximum allowed distance is but the Amp is located in a metal rack in an attic closet on the second floor on different side of the house.