App crashed when trying to select word

Expected Behaviour

One should be able to select the word, or the UI should be refreshed, so the word could not be selected.

Actual Behaviour

When one chooses a certain number of letters, let's say 7.

Immediately after that, one changes into another number, let's say 14.

Selecting the word will crash the app.

Steps to reproduce

Launch Crossword on Android 8.0.0

Choose a certain number of letters, let's say 7.

Change the number of letters into another number, let's say 14.

Select any word at all.

Testing Environment

Device: Honor 8 Pro

Model number: DUK-L09

OS: Android 8.0.0

App Version: 1.06

Notes: App downloadable on F-droid

Recording of bug