This comes from California's Instructions Guidelines for Determining Residency Status (FTB Publication 1031) :
"However, if you file a joint return and either spouse/RDP
was a nonresident or a part-year resident in 2020, file
a Form 540NR, California Nonresident or Part-Year
Resident Income Tax Return."
You need to go to the beginning of the California return and manually select the California nonresident return. If you do not have that option, you may need to contact customer service.
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