Scientific websites and portals are not always popular and usually do not have as many visitors as entertainment sites. The admin sees that there is little traffic and does not check the site very often. It is easier for them to block copying than to monitor the site’s internal inbox for requests for text materials. They may respond in the future, but as I understand it, you need the text right now. You can copy it even without using special software, since there are online services for this. You can try this tool, for example:
https://pr-cy.io/page-to-text/ . It extracts the text from a page in just a couple of clicks, and you can copy it immediately.