Product Specification table does not update

i have used this plugin

https://www.ads-software.com/plugins/product-specifications/#developers

its an amazing plugin

but i have some issues with it

When I add a new attribute to an existing table, the products already using that table, the attributes does not get saved.

So for example if i have an existing table for ‘Shirts’ which has already used for products e.g. shirt 1, shirt 2 and shirt 3.

But now I am adding a new attribute to the table ‘Shirts’ which is ‘Colour’

Now when i go to shirt 1 and update the colour attribute and save it, it does not get saved.

I tried clearing cache, deleting the table and making a new one but nothing works