www.wysiwygwebbuilder.com

In WWB 21, older projects (v18) load with correct LayoutGrid names in Object Manager, but the Properties panel resets them to LayoutGrid1, 2, 3... Saving the project permanently overwrites custom names.

I am not aware of any issues in WWB21. I am using this feature daily without any issues also no other users have reported this.
Can you please be more specific?
Do you have a DEMO project?