Mixing Wireless & Wired - RBR50>RBS Satellites

Hi, I have an RBR50 and 2 x RBS50 Satelites. They connect as a wireless diasy-chain set up like this:
Virgin Broadband Modem (modem only mode) > Cat7 wire > RBR50 Router > wireless > RBS Satelite 1 > wireless > RBS Satelite 2

It works fine, most of the time, but there are often issues with the 2nd sSatelite becuase it's quite far away from the 1st Satelite.
It's mostly a 'blue' connection, but sometimes shows as Amber. (It's in a garden office and at the limits of the range of the 1st Satelite). Therefore, I have connected a CAT8 cable from the 1st Satelite and run it to the 2nd Satelite acros the garden to try and resolve the problem.

The Router and 1st Satelite are still connected wirelessly. (It's difficult to wire these together becuase of house walls etc)

The new set up therefore looks like this:

Virgin Broadband Modem (modem only mode) > Cat7 wire > RBR50 Router > wireless > RBS Satelite > CAT 8 wire > RBS Satelite

Problem is I am noticing sudden unexplained drop-outs with the 2nd Satelite (more so than when it was wirelessly connected) and am assuming there's a configuration I need to make in the Admin to allow for this hybrid wireless/wired Daisy-Chain to work.

Any advice?

(Latest Firmware on all Orbi as of 29/04/2021)