How do I set and display the closing % for the fyrtur blinds?

The ‘prediction’ comes from autoupdate, which is guessing the likely outcome of a command. When the prediction is for ‘no change’ it generally means autoupdate thinks the channelis broken is some way.

But - you have a Zigbee device, and Zigbee binding sometimes vetoes autoupdate.

A possible cosmetic improvement for you is to force autoupdate.