Very major bug: cannot use search bar in Word if opening PDF

Using either beta or normal swiftkey, using the search function will cause it to become unusable.

https://gfycat.com/carefreecornyfunnelweaverspider

Gboard works fine. Works in Google Drive PDF opener.

Using Huawei Mate 20 pro, reduplicated in huawei p20 pro in android 9 and 10.