What do you mean by slow AP125 ?
- The performance for you to get to any network resources ?
- Slow for you to connect ?
Please run the following command :
show ap arm history ap-namee <apname> = This will show you if there's many channel/power changes and reason
Also when this happens how many users do you see connected to that AP :
show ap active = will let you know how many users are connected on "a" and "g"