ios 13.1.2 audio stuttering with hoopla digital

Hoopla audiobook digital playback is stuttering or skipping after I installed IOS 13.1.2 on iPhone 7. No issues with Hoopla earlier.

I restarted phone, deleted/reinstalled hoopla app, no improvement.

audiobook playback on Audible is fine, so this is specific to hoopla and IOS 13. Sound skips about every 10 seconds or so. Tried on more than one audiobook, same issue found.