Meta Tags description

Hello there.

I am working on version 2.0 of my store.
Everything is up to date.
For now it is “comming soon” mode.
I’m in the chapter “basic seo settings before go live”.
I have activated the option to discourage search engines.
However, 3 products “escaped” into Google and were indexed.
That’s how I discovered, that the meta description is not displayed correctly. More precisely, it displays something else.
That is:

I use the “Woocommerce Single Product Page Customizer” module. It displays under the product description, in a new tab (for all products in the store), a small disclaimer, through which attention is paid to the correct use of the product, reading the manual,…

For all three products that were not indexed on Google, “site:mysite.com” appears on the check as the description of this added disclaimer.
As a variable in the settings, I use global %excerpt%

At the same time, using a google-chrome extension (seo-minion, which also works if only the admin sees the page), things are displayed correctly, both in the seo analysis area and in the serp preview area.

How could I solve this situation please? Another variable? A possibility of bypassing what this plugin displays, for rank math?…?…?

Thank you.