Stock status not showing with the plugin enabled

Hey!
Just bought the plugin, installed and looks good.
But we use plugin – https://woocommerce.com/document/custom-stock-status-3/
And it shows is it in stock ready to ship or not (on product pages)
With your plugin enabled, it shows only for like 0.5 second and than disappears.

Here is a link to video loading prouduct page:
https://streamable.com/i7bmwx

We disabled the plugin.
Please help.