AP15 Support

Dear all,
I purchased 25 pieces AP15 to replace the old unifi AP in a school, but I am not happy with the signal coverage. If I am 3 meters away from the access point I get fair signal. No walls, no barriers. 
Any idea? I have to sit next to the AP to get good signal. It's not normal . 
Please advice @

Please reach out to support to investigate your signal issues.
https://community.arubainstanton.com/support/contact-support
Original Message:
Sent: 02-13-2021 01:52 PM
From: Unknown User
Subject: Poor WiFi signal on AP15

Dear all,
I purchased 25 pieces AP15 to replace the old unifi AP in a school, but I am not happy with the signal coverage. If I am 3 meters away from the access point I get fair signal. No walls, no barriers. 
Any idea? I have to sit next to the AP to get good signal. It's not normal . 
Please advice @