We have some mobile-friendly issues affecting /domains/.well-known/

This page simply displays:

Index of /domains/.well-known
Parent Directory (a link)
pki-validation/ (a link)

Do the mobility issues for this page affect the site overall? i.e. will there be any penalty that affects the site, or is the penalty applied to the page only?

Should I add this page to the blocked pages in robots.txt?