Just tried an EX8000. Was unable to extended the AX6000 Orbi network

Just in the past 24 hours I (1) updated my RBK852 firmware to the latest and (2) added my EX7700 as an extender to the system.  I had mothballed my EX7700 a year+ ago from my C7800 modem/router because it kept dropping (C7800 did not have mesh capability -  another deficiency of my old setup).  Let's see if it still drops.   My 2-piece RBK852 system was great, but in 1 corner of my 3 story house I was only getting <200mps down / <15mps up  (Comcast gigabyte), although most of my house was pushing +600mps down / +40 mps up.  Now, with the extra extender, my whole top floor is >400mps down / ~40mps up, because now all equipment shifts to the EX7700 on the 3rd floor.  Before adding the EX7700 there were a couple of 3rd floor rooms reaching the 600mps down area, but now they have been negatively impacted.     

It seems my EX7700 is synced to the router (vs. the satellite on the middle floor).  Would the EX7700 ever get its signal through the satellite?  

Update, I now have flipped my satellite to top floor and EX7700 to middle floor.  Ultimately what I am left with is a scenario where I can have most of my house at 600mps and a few rooms <200mps (ie, no EX7700) OR have 2/3 or my house at 600mps and 1/3 at 400mps (when equipment synced to EX7700).  I'm half-hoping my EX7700 drops a signal like the old days because that will make my decision easier.  I guess at this point these are all tough 1st world problems to have?