Along with #958 and #953, this seems to be a bug in the LUNA code where initial conditions at the start of the growing season for Vcmax and Jmax are hard coded to the same value, globally

Extensive discussion can be found in #947, where @lmbirch89 has suggested using values from the last day of the previous year so that there's some climatological memory of appropriate LUNA parameters at the start of the growing season.

It likely makes sense to bring this into #961, where previous bugs were addressed to evaluate the impact on global simulations