Topology: 1 x AX5400 router, 4 x RE705X easymesh extenders

I have upgraded firmware on 3 of the extenders from 20230509 to 20250627.  All our used to show medium to strong signal strength prior to the firmware upgrade.  The three extenders that I upgraded now show 1 red bar in the AX5400 management page.  The fourth, which is still running the old firmware, continues to show a strong signal.