Hi @Margaret_Picker, unfortunately there is no way to disable the resolve option right now. It is a missing feature.
Resolved comments do not disappear completely though, you can still find them by opening the comments panel on a record and switching the view from "All Comments" to "Resolved Comments" at the top. They are just separated from the active ones which is exactly the problem you described.
One simple workaround in the meantime: instead of resolving comments, just use a ✅ emoji at the start of the comment to mark it as done. Everything stays visible in one place and nobody misses anything.