I have a Pentair 7 186237-01 pool pump. the capacitor was replaced 1 year ago. it is acting like the capacitor has failed again. did they put on the wrong capacitor?

No
capacitors either work or they don't work
being electronic and subject to surges and spikes they can last many years or just months
there are various qualities of capacitors but even that is no guarantee of long life
you can check if the capacitor is correct by getting oll of the details off the plate on the motor( volts, current , rpms , hertz-phase , cycles etc and with that information take the failed capacitor to an electric motor repair shop and they will know if it was correct or not
the requirements are correct voltage and mica/peka farads required to start/run the motor
there is a permissible range but outside that range , the capacitor is wrong