Range Extender - How do I know if its connecting to Base or another range extender

Hello: I have a 3000 sq foot home, one level. The base in centrally located. I have 3 range extenders setup like this basic Diagram. All extenders are Gen 2. All sensors seem to be working from all extenders. Extender 3 ------Extender 2 -------- Base Station ------- Extender 1 Extender 3 is in a garage, more challenging environment but is line of sight via one door to Extender 2 at a distance of 20 feet away. The base is through three walls and 30 feet away. The symptoms I am having is that the extender in the garage shows weak signal. Today the extender 2 showed weak signal. I go to the advanced options, use the reconnect function and press the round button on the extender connects and the poor signal indicator goes away. The Garage Extender was a replacement from Ring as the previous one had the same symptoms. So, I don;t think its Extender 3 at fault. I also have a new in box extender. After looking at the specification, I don;t think I need 4 extenders to solve this, do I? Questions: 1) How can I confirm that Extender 3 is connecting to Extender 2 and not the base station? 2) Any suggestions from the community to keep the extendors from showing weal signal when they are only 20 feet away from another extender and 50 feet from the base unit. Thanks in advance,