Flip side. Only a very specific few things could cause 1/2 of this like you described. Massively warped/bent rotor(s) is one (brakes only) pushing pads back into calipers causing multiple pedal presses to regain contact. Wife would have complained of other issues first.
Close up pic of abs module/brake controller if possible? I’m only giving advice based on MY previous experience. If the issues feel digital (1’s & 0’s/on-off) then it’s probably electronic related.
Just use Discount Tire. They keep next to zero records. I live on a SHIT TERRIBLE dirt road. I told them that up front. They just keep replacing tires for $22 warranty extension.