On your capture, you can't see this CTS frame, because you filtered with the module's MAC address.
As stated in the previous message, we are already using WICED 6.2 (we will try 6.4).
The only CTS frame with Broadcom OUI is the first one, just before the Authentication frame.
The subsequent CTS frames contain the Murata OUI.
By the way, what bothers us is not this CTS frame, it's the duration of the join process, more precisely the delay between the probe response from the AP and the authentication frame from the module (almost 1 second), causing massive loss of audio frames during roaming.
This delay can easily be checked with the powersave app (POWERSAVE_STANDALONE_TEST_* set to zero), using the join_specific command (you have to set the bssid and channel parameters).
We have tested WICED version 6.4 this morning, same behavior.