Swipe up or down doesn’t work

Same issue here - it started after the last update for me. (8.5.1 version). Resetting (holding the crown & side button simultaneously) does fix the issue - but only temporarily. Hoping Apple is working on a permanent fix.

Reset the Watch, it will not affect your data. Press and hold the Digital Crown and the power button together until you see the Apple logo and then release. The Watch will reboot. Test.

Same for me, swipe up to see charging level stopped working around May 20th. Thanks for solution, that has fixed it.