How to install the newest version of a package?

I can’t replicate.

$ mkdir /tmp/testdepot                   # Create an empty depot.
$ JULIA_DEPOT_PATH=/tmp/testdepot julia  # Start Julia 1.10.4 like freshly installed.
(@v1.10) pkg> add KiteModels@0.6.3       # Add 0.6.3 to global environment.
julia> using KiteModels                  # Load it for good measure.
(@v1.10) pkg> activate --temp            # Create an empty environment.
(jl_kSO7yU) pkg> add KiteModels          # Add KiteModels, installs 0.6.4.

Do you have a startup.jl file?

Does

pkg> activate --temp
pkg> add KiteModels@0.6.4

work and/or give any interesting output?