|There are several rules of thumb one should live by when it comes to computing. In no particular order, they are:|
2) If it ain't broke, don't fix it.
3) Whenever possible, always use equipment from the same manufacturer.
If it were me, I'd reset the extenders to factory defaults and reconfigure them and see if they don't begin working properly. Of course, I'd RTFM before attempting to reset and reconfigure them.
If you absolutely can't get them working with the "apple" router, I'd exchange the apple router for a Linksys wireless N router.........which you should have done in the first place since all your other equipment is Linksys.
Just FYI, Mac (apple) equipment, most specifically their networking equipment, is well known for not workining well in a mixed environment with other vendor's equipment.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.