I am not so sure but you might be hitting one known issue where AP with static IP could not establish SSH session with controller.
SSH into the AP and run below command. rkscli: set ipmode wan ipv4 OK
To verify: rkscli: get ipmode wan IP Mode: ipv4 OK
For permanent fix, please refer below article.https://support.ruckuswireless.com/articles/000010443
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