I've bought new iPhone SE 2. I've made synchronisation from old iPhone SE (iOS 12.4) to new iPhone SE 2 (iOS 13.4.1). SwiftKey has been automatically installed with full access and SwiftKey Flow turned on (done automatically via iOS synchronisation). When I've tried to write some word in any type of application with SwiftKey set as primary keyboard, the SwiftKey Flow seemed to have problems with gesture recognition and keyboard was shaking all the time like it can't figure out words.
Only fix that I've been able to come up was to uninstall manually SwiftKey and install from App Store and set access rights in the settings again.