Updated my iOS version to 4 (4.0.0 build 847) today, but keeps hanging at the “Sync Setup - Setup Your Sync Key” splash screen. I can dismiss the page, and so can access Codebook. However, it does not allow me to choose whether or not I have created a Sync Key (which I have on the Windows 10 application). The soft keys (yes / no) are not functional. The ? prompt remains touch sensitive though.
Navigating to More --> Sync --> Setup Sync Key has the same problem.
Using on iPhone 8+ running iOS 13.2.3