1 | initial version |
If it's open, there is no encryption so there is no need to decrypt to see the actual data payloads sent between hosts. What you are likely seeing are management and control frames; these do not require decryption but also do not contain payload data that you might want to see.
To see just data, try a filter such as
wlan.fc.type_subtype in {0x20 0x28}
If you have a capture from a monitor mode device, then this filter should hide the management and control frames and just show data/QoS data frames. For a network that is open, the payloads here will be visible (for example, might be http, dns, whatever).