The Japanese input has recently had this annoying problem. The typing is normal, but if I try to enlarge the prediction box by pressing the downwards pointing arrow, the predictions become unusable.
The same thing happens on landscape mode:
The predictions apparently work normally, since pressing those huge buttons doesn't give the right prediction. They are only drawn like that. For example, pressing the right edge of the "the" prediction would give "www.google.com" as a prediction instead of "the."
I tried deleting all data from Swiftkey, but the Japanese predictions worked normally only for about one minute while I was adjusting settings. Reverting the settings to normal did not fix the problem.
My device is Samsung Galaxy tab A model SM-T585. I have the latest device and Swiftkey versions. I have android 8.1.0. Swiftkey is version 22.214.171.124. This problem has been present for several months.