Show Widget on Selected not working in one single case?

Hi,

I have been using your plugin for a year or so and it worked like a charm until today.

I have several widgets shown on certain pages on the basis of the Show Widget on Selected logic by declaring their URLs.

Now I am trying to add a widget with a menu on a certain page.

I add a Navigation Menu widget, choose the menu, select Show Widget on Selected with Target on URL and specify the page URL slug like I have been doing so far and many times.

However, the widget does not appear on that page.

I am using WP 5.8.2 and have restored the classic widgets through the plugin made by the WP developers.

I have a total number of 44 widgets so I wonder: does the plugin have a max. number of widgets supported?

I can not supply the page URL because it is published in a private area of the website.

Thank you