yea skies dont work on 1.21.9, that is with beautiful skies on, with fancy graphics on, with simple graphics on or vibrant visuals on, this is a reallyyyyyyyyy bad problem. Ive been working on a pack for 4 months with my staff team and for minecraft to just mess up skies in this update yk is really bad for us especially considerng it's a bridging pack and wont feel good at all without a good sky. Please fix this asap for it's really bad for bridgers and pack makers
This issue is being tracked at MCPE-221318.