It's always best to setup a fiddle to see if the problem only exists in your code or if this a sencha problem. I created a fiddle for you and it seems it does not show the problem.

I added comments to all problematic parts in your code:

https://fiddle.sencha.com/#view/editor&fiddle/3sk2

A problem could be using IDs.

Its problem in ExtJS , steps to reproduce:

You need Chrome : Version 131.0.6778.86 for now its lattest

In chrome go to chrome://accessibility/

Check this to active Web accessibility

Open this fiddle https://fiddle.sencha.com/#fiddle/1n7s&view/editor Select version: Ext JS 6.2.1.167 - Classic

and try to just show or hide columns in menu or just move mouse on column menu.