Please deactivate all the plugins not related to the theme and switch the parent theme, check the issue, if the problem remains, leave the plugins not activated for us to check.
Seems like this product has some wrong HTML markup in its short description https://gyazo.com/cf45f178c8d9fd3e7451eaf23b9b0c47
Review its HTML code via Dashboard or try to temporarily remove the description completely and check how it works.