Macbook wifi automatically connecting to router extender rather than main router

[Chris49]

Hi,
I have a macbook pro running OS Catalina 10.15.7.

Recently I have noticed that my mac automatically connects to a router extender located in an annex building in preference to the main router in the house, for which the signal must be stronger. I have 'automatically join this network' selected for the main router.
I can manually connect back to main router and it stays so connected until the mac re-starts.
I'm not sure if its doing this 100% of the time as I often don't notice unless the connection to the extender is slow enough to be annoying.

I'm not aware of any setting or environment change.

There's probably a simple explanation, but not simple enough for me unfortunately;-)

 

[Cory Cooper]

Hello,

Give this a try: How to Prioritize Wi-Fi Networks on a Mac

I would bet that your network is below the other in the list and reordering should fix it., especially if they have different Wi-Fi SSIDs.

C

 

[Chris49]

Thanks. Just picked this up.

My router was indeed below the extender on the priority list. Have just redressed this, so I'll see if that was the problem.

I wasn't aware of this feature so am not sure how they got to be the wrong way round.

Many thanks.