Possible iOS-13 and Audioquest Dragonfly Red compatibility issue

Here's my problem: I replaced my now obsolete iPhone 6 with an iPhone 11 (iOS-13.1.2). I am using an Apple Lightening-USB 3 camera dongle (it has a Lightening power/charging port, a Lightening phone connector and a USB slot) to connect a set of Etymotic Research ER4-SR earphones to the iPhone. The ER4-SR is plugged into the Dragonfly which is itself plugged into an Audioquest Jitterbug. The chain is:iPhone 11-->USB-3 connector-->Jitterbug-->Dragonfly-->Etymotic earphones.

This set-up functioned perfectly with the iPhone 6 using iOS-12 but it doesn't work with iOS-13 on the new phone. Interestingly, this ensemble continues to work flawlessly when playing AudioEngine A2+ speakers (wall powered) with both the iPhone 11 and also with the iPhone 6. 

When I insert the USB-3 connector-->Jitterbug-->Dragonfly-->earphones into the iPhone 11, the Dragonfly "powers up" but there's no sound transmission through the earphones. I've removed the Jitterbug and just used the Dragonfly + USB connector + earphones: same problem. I've checked the phone's Lightening port with the Apple-supplied Lightening earbuds and they work. I re-tested the Etymotic earphones in this chain connected to the iPhone 6 and they work. So, it doesn't seem to be component failure.

In summary, as far as I can tell I've sequentially tested each component of this chain and everything works except when the ensemble is plugged into the iPhone 11 separated from external power. Based on all this, it seems to be a power issue. 

I've called Audioquest and spoke to someone in customer service. He is not aware of any incompatibilities. 

I've ordered a Lightening-->3.5mm connector so I can use the Etymotic earphones without the Audioquest components. A compromise that falls short of audiophile standards but hopefully it will work.

Any insights? Have I overlooked anything? Has anyone else had a problem of this sort?