And if all else fails completely re-flash the AP using the process and u-boot loader at https://www.cisco.com/c/en/us/support/docs/wireless/catalyst-9120axi-access-point/217537-repairing-c9120-c9115-access-points-from.htmlNote although the subject only mentions 9120/9115 the ...
C9120AXE-H Place of Origin Guangdong, China Supplier Type ENTERPRISE Model C9120AXE-H Type Wirless AP Dimensions 8.5 x 8.05x 2.0" (21.6 x 21.6 x 5.1 cm) Weight 1.36kg DRAM 2048 MB flash memory 1024 MB Warranty 1 Year Condition