With the Breadcrumb plugin, there are always error messages in Google Search Console. The "ID" is missing the "https:" at the beginning of the URL. The problem exists only with deep links.
It is about this one for my page:
But the problem also exists with the other subpages.
Screenshots from the GSC:
Welcome to our forum.
I can see http:// or https:// is missing with URL, could you please go to settings page and check the "WordPress Address (URL)" and "Site Address (URL)" you probably missed to put https, please see the screenshot