When trying to capture for example a session between an application running on an iPad (master) and a Bluetooth device (slave), if the analyzer capture the Attribute Protocol interactions between the two but shows anything higher in the stack than the L2CAP layer , then its a security issue.
In order to solve it, see the keys icons on the top toolbar – being red meaning that the messages are encrypted but the analyzer were not able to decipher them.
Please open the network keys form by clicking on the keys and set the depth to 20, Then reopen the file.
If this doesn’t help – either some of the pairing messages were not received by the analyzer, maybe you used a PIN code and you should enter it or let the analyzer find it.
Recommended 1st step to captured entire session, starting with the devices not paired and then pairing , 2nd step is going through the GATT tests.
Perytons support can also help by sending them the anlb file and they will check it.