Jane, does your theme have a place to add custom css?
You could add this:
.comment-time {
pointer-events: none;
cursor: default;
text-decoration: none;
}
It’s one solution I found for disabling links. I tested it in Chrome dev tools and it seems to work for me. If you can’t add the css from within the theme you may need to make a child theme.
Edit: Ah… just saw your reply and that you now have a fix.