Constraint not evaluated for calculate type

Hello @Kal_Lam,
It seems as neither ODK nor Enketo is evaluating a constraint clause for a calculate type.
Is this conform with the XLSForm specification?
Probably the same for a hidden type?
Could we have a hint in the documentation, please?

Here a simple example
Calc_Constraint01.xlsx (12.2 KB)

cc: @Xiphware