From the QA-ops perspective:
product designers, product owners and this kind of people are often very "soft" with product requirements. They often put a lot of prio on function requirements but not on non-functional requirements.
There are some UX lacks when things doesn´t happen as desired. Developers did the job, they stick to the mocks to deliver incrementals ASAP.
I wouldn't call bugs, because it has something related with UX and then they must do something about as well. In the other hand, defects are considered on testing stage so,
is it a defect?
add your thought if needed: how would you call them? (I would call it defect as well but the definition sticks to testing)