in a WLAN network with a tunneled SSID.

This indicates a security issue. The client with a MAC address ending with 37 18;0d Is performing a Denial-of-Service attack on your network. You should track down the client and remove it from the network.

This is normal, expected behavior. No further actions are needed.

This indicates a client WLAN driver issue for the client with a MAC address ending with 37:18

:Od. You should upgrade the client WLAN driver.

There is a roaming issue Enable Fast Roaming 802.11r and OKC to resolve the issue.