The satellite in question is one floor below ~25 feet away

It might be helpful to lean more about WiFi coverage in the house.  There are "Heat Map" applications for many platforms which allow the user to walk around and record WiFi signal strength at various places.  After being told, "the WiFi is not very good in the bedroom", I installed WiFi Heat Map (by Webprovider) on an Android tablet.  Walked around the upstairs and recorded this:

Oh, dear.  GREAT WiFi signal in the room where the Spectrum modem and WiFi router are located.  (This was install SO many years ago!)  After about 36 ft. and four walls, the signal had dropped to -76dB.  Installed an Orbi satellite in the bedroom and did another "walk":

No more complaints!

p.s. I find the ENORMOUS X's marking where readings were taken annoying.  But, it is a free app.

Often there are "things in the walls", such as HVAC ducts, chimneys, etc. which can affect the WiFi connection between router and satellite.  It might be worth experimenting with moving the router & satellite slightly to different positions to see if one is more stable.

I don't see with my 870 series online currently. RBS wirelessly connected. Most any distances less than 30 feet in between the RBR and RBS, you may see issues. 25 feet or less is too close in between the RBR and RBS.

What is the size of the home in sq feet? 

Only one RBS or more then one? 

What FW version are you using?