Hello and thank you, Sharif @smeunus!
Apparently, the link on the staging area goes into the live site and the custom php snippet I mentioned above have not been implemented when I sent the support request earlier.
I saw that it is now working great both on the staging and the live site, although I just noticed the SALE (%) label disappeared on the “Popular Product in Category” and “Related Product”
Maybe you have some thoughts about it?
All the best,
Sam