Can't add comments to custom list on mobile

Usually I edit custom lists on desktop but currently I don't have my laptop with me and won't be able to access it for awhile. When I click on add comments on my phone, nothing happens. The title jiggles as if I'm trying to rearrange it but I can't add any comment to it. I'm using my phone browser.

Even switching to desktop version of the site does nothing. How can I edit the custom list with comments and not simply add and rearrange titles?