Thank you, tuanphan!!
I received a message from Squarespace saying that the additional padding beneath text links is related to an issue on their end, which their engineers are working to fix. The problem only affects certain fonts such as Aktiv Grotesk.
I used your code, but increased the line-height to 18 px. This worked, but only for the links on the homepage. Is there a way to target all links? Or will I need to add custom CSS for each type of link throughout the website? (For example, the footer link underlines are still too low.)
There is now a new problem: Long link text will not break into two lines as it did previously, resulting in large holes in the text. (See image.) Any advice?
Thank you for your help!