How to properly document UX bugs?

What is your advice on creating titles for User Experience and usability bugs?

We are using a spreadsheet to report and track software bugs, including UX bugs. We have divided the bugs into the following categories:

  • Functional Bugs
  • Visual Bugs
  • Usability Suggestions

So far, most of the issues related to the flow of the app and interactions thereof have been categorized as Functional. One of the feature suggestions or usability improvement suggestions have been put under the Usability Suggestion, but it is somehow hard to make a clear distinction between categories.

I have read some bug report samples but they are mostly related to back-end and technical issues and little issues related to interaction, UX and usability.

I wanted to ask for your advice and ask if you could provide me with various examples.