Issue when changing grid size or word length

[iamdenzen]

Hey,
I want to increase the word length to 8 from 7 and decrease the grid from 1515 to something like 1212.
but as soon as I change the values in the code. It stops working:

Uncaught TypeError: Cannot read properties of undefined (reading '0')
    at Board.isAllClearVertical

The errors are random on each page reload.
It works in 1 out of 3 reloads after changing.

Please help.

Thank you.