Zenbeats looses MIDI Clock Sync on iPhone

[OmskInfo]

Anybody else notice this? I've got Zenbeats installed on my iPhone 8 and I'm connecting it to my MC-101 via the basic Apple Camera Connection Kit (the one without the additional power input). I'm turning the MC-101 on while holding the [VALUE] knob so that it doesn't try sucking any power from the iPhone. I can stream audio from the iPhone to the MC-101 (the MC-101 is set to the Generic USB driver) so all is good.

I load up Zenbeats and can configure it as either the MIDI Clock Master or MIDI Clock Slave. When it is set as Master and I enable play in Zenbeats, the MC-101 starts playing as it should. Similarly, if I set Zenbeats as the Slave and enabled play on the MC-101, Zenbeats starts playing along. So, all good there, too.

HOWEVER...

While playback always starts with tight sync/alignment between the two, Zenbeats and the MC-101 gradually start falling out-of-sync with each other. Happens in either of the Master/Slave configurations I describe above, though I think the sync deteriorates faster if Zenbeats is the MIDI Clock Slave. And the behavior isn't consistent—sometimes the sync will remain tight for a while before it suddenly "shifts" out, while other times the shift happens very soon after starting playback.

Is anybody else experiencing this? I'm assuming a MIDI Clock Byte is getting dropped somewhere between Zenbeats and the MC-101 which causes the shifts.

Of note: sync remains _perfect_ when I use Garageband on my iPhone. So this seems to be a problem specific to Zenbeats.

This is Zenbeats version 2.2.0.8408 according to the About screen. I'm running iOS 14.7.1 on the iPhone 8.

[NormalHuman]

I know this is well late but it's the same for me on android Zenbeats will not stay in sync with any external gear using a USB to midi lead.