Photoshop 22.1.0, Win 10 x64. Regardless of image size/pixel count, Select and Mask DOES NOT display LIVE masking. The previous version worked fine until the 21.1.0 update broke it.
Here is a 1500px image (long side) with Select and Mask options enabled at Maximum/100% - note that no mask changes are evident. NO changes affect live mask updates; selection remains static: If I invoke Select & Mask after my initial selection, the mask will show an updated selection but it is NOT able to be modified: If I accept these changes, the image reopened in Photoshop will show an updated mask:
In other words, the Select & Mask feature in Photoshop 21.1.0 has been rendered useless. Please restore proper functionality ASAP. Thank you.