change mobile break point

Can you please provide some guidance on changing the mobile breakpoint? I found another post regarding this and changing 768px/767 to whatever values you wanted un various files, this did not work for me. The hamburger menu would appear at the correct width, but the off canvas would not appear when clicked, nothing happened.

Thanks for any help on this.

I can create credentials. Any chance you can send the file names where the breakpoint needs to be changed so that i am aware of where the change occurs? Thanks