Post terms are threated as default links

Tags and categories in post meta and elsewhere are underlined if links are set to be underlined by default. Removing underlining for the block only affects the prefix and suffix, not the actual post terms.

Block editor:

But this CSS is the actual output.

a:where(:not(.wp-element-button)) {
  color: var(--wp--preset--color--contrast);
  text-decoration: underline;
}

The same thing doesn’t happen in Twenty Twenty Four which outputs:

.wp-block-post-terms a:where(:not(.wp-element-button)) {
  text-decoration: none;
}

(Tested with a clean install, no plugins).