Table of Contents block - When setting Columns to 3 columns, it's displaying 2 columns both in editor and frontend

[andeng1106]

Describe the bug When setting Columns to 3 columns, it's displaying 2 columns both in editor and frontend. There's a bug happening in editor, if the block is selected, it displays 3 columns but if you lose focus and select other block, it displays 2 columns.

Note: This issue also happens on Wordpress 5.9 but it might be nice to fix this.

To Reproduce Steps to reproduce the behavior:

1. Add many blocks to fill the table of contents
2. Add a table of contents block
3. Set Columns to 3
4. Update changes
5. Check frontend if there are only 2 columns
6. Check backend if there are 3 columns
7. Try selecting other block
8. Check table of content block in backend again if there are only 2 columns

Expected behavior If Columns are set to 3, it should display 3 columns both in editor and frontend.

Screenshots

https://user-images.githubusercontent.com/103395655/168253956-ec363c9c-ebc1-411c-be8b-cdbf0ad979c4.mp4