"Confirm payment" button doesn't respond for c60 seconds

Issue:
When app pops a “Time to verify your online payment!” screen, the black “Confirm payment” button fails to respond to taps.

How to reproduce it:
Make a payment e.g. Curve-fronted in iOS, the button appears, tap it dozens of times - nothing happens, then eventually it responds. Unclear if (1) the button is unavailable (albeit showing in black) for a time (c60 secs), or (2) it registers the first tap but then is waiting for some process to complete before acknowledging about 60s later, or (3) it requires dozens of taps to register.

Seems to happen for any largish transaction - Curve-fronted - irrespective of the underlying funding card.

OS:
iOS 13.7
Device:
iPhone XS Max

App version:
3.5.8

Screenshot:

I have the very same experience on iOS.