I have encountered some movies on Disney+ that don’t display the resolution selection. It’s blank and the dropdown doesn’t work.
So far I have noticed it for:
X-Men (2000)
X-Men: The Last Stand (2006)
X-Men: First Class (2011)
X-Men: Days of Future Past (2014)
X-Men: Apocalypse (2016)
X-Men: Dark Phoenix (2019)

Anyone else with this issue or is this on my end?