To sniff BLE traffic effectively, it is important to identify the device which could be advertising on any of the three advertising channels. For this, it is important to have a setup of three Ubertooths rather than one.

Additionally, some of the other tools you can try out are:

• btlejuice: This is a handy tool if you would like to perform MITM on BLE traffic with a web GUI interface
• Gattacker: This is similar to btlejuice but without a GUI
• BLEah: This is a BLE info-gathering tool