Dear Arune,Please try to assign power level of AP's 5 Ghz and 2.4 Ghz manually from Configuration > Wireless > Access points > 5 Ghz Radio and 2.4 Ghz Radio at controller. Power level depends on the distance of APs and if APs are installed in symmetr...
Dear Mosasa,Please refer this release note https://www.cisco.com/c/en/us/td/docs/wireless/controller/release/notes/crn85mr4.html and it clearly written there that AIR-CT8510-K9 controller supports AP AIR-CAP2702I-B-K9 model.Good Luck..