Can’t ping wireless to wireless

Was hoping somebody could provide some insight for me on a weird behavior I am noticing. I am fairly to new to this environment and trying to troubleshoot a network I did not setup or have great knowledge of. What is happening is I can’t seem to ping wireless machines from other wireless machines. However I can ping the wireless machines from a wired PC and vice versa. the wireless machines work fine, I just can’t ping wireless to wireless. We have an ASA 5520 firewall and Cisco 4400 WLAN controller. I don’t know if it’s related to either of those or something totally different. Why would I be able to ping wireless-wired/wired-wireless, but not wireless-wireless? Thanks!