After posting this update, I then tried (again) the following:
clear profile from iPad runing 17.7.3
downloaded the iOS bluetooth debugging profile to my Mac
AirDropped this profile to the iPad
reboot iPad (with USB wire disconnected)
start PacketLogger on mac running Sequoia
Amazingly, bluetooth packets started coming in once more. I had already followed these exact steps, except previously I downloaded the profile directly on the iPad (rather than AirDrop from the Mac).
For whatever reason, I am again capturing Bluetooth packets. Hopefully you can try these steps to see if they help you too.
Topic:
Developer Tools & Services
SubTopic:
Instruments