Hello Aviv,
I just tested an AP7532 v5.9.2.5-001R with several wireless clients associated (e.g. laptop, MC92N0, and Android) on a defaulted config (just wlan) and cannot duplicate the issue.
I strongly advise upgrading to v5.9.4.1 and see if the issue is still present.
We would require a tech-support from the AP with the wireless client associated and possibly a wireless capture if issue is still persistent.
Please have a support case generated so one of our specialists can assist.