Read the edition, not the poster
A high-resolution poster does not establish video quality. Open the film's viewing options and check the available HD, 1080p or 4K edition. A service can offer different resolutions according to its plan, device support, or the particular release.
When Auto is the comfortable choice
An automatic setting lets the player respond to changing bandwidth. If a fixed high resolution repeatedly buffers, a stable lower setting can make the evening much more enjoyable. Try it before assuming that the title itself is broken.
Resolution is only one part
Compression, contrast, display settings and the source affect the image too. HDR and surround sound are additional features, not synonyms for 4K. Check the equipment and the edition together if those features matter to you.
A worthwhile test scene
Look at a short stretch with movement, dialogue and a darker area. Confirm that the picture, sound output and captions behave sensibly before committing to the whole film. The bigger-screen collection offers films where an edition choice can be worth the extra attention.