Since Rel. 4.23 (approx. ?), the two-sided PIB is no longer created (the circle spins indefinitely) when a Wi-Fi connection is present.
Possible hint as to the cause: If you turn off Wi-Fi so that no current METARs and NOTAMs are loaded and inserted into the PIB, the two-sided creation of the PIB works.
Hello Martin,
the problem is not new.
The background is as follows: For rendering the double-page view, two pages must always be kept in memory at the same time. This can lead to memory limitations on some devices.
It is particularly dependent on the NOTAM list, as this can sometimes be very long.
I will, however, raise the issue internally again to see whether we can make further optimizations here. 
Aviator greetings
Hermann
I have that too: Everything’s fine on my smartphone. On my old tablet there’s no two-sided NOTAM Bulletin. But I can live with that 