Notability doesn't sync notes from icloud

A week ago I bought a newer iPhone and transferred all my data. I've been struggling with this bug all week: sometimes apps simply won't launch, and when I press the share button, nothing happens. The only thing that helped was rebooting, which I did 5 times a day everyday. Then everything repeated itself. Of course, I wasn’t going to reset the iPhone and set everything up again, because it’s Apple’s fault, I don’t want to lose all my data! I sat down and began to fight with each application separately (of which I have 100+). In the end, I found the reason - Notability. It doesn't want to sync notes from icloud, it freezes and crashes. All you have to do is delete it and all apps and the share button work immediately. icloud displays all my notes from Notability, but they are not downloaded in the app itself. Why?