Issues Sending Multi-Select Fields to ActiveCampaign with the Add-On

I’m using a Multi Select field for US states (for business locations) in a form, which is connected to a List Option field in Active Campaign. (The List Option field type in Active Campaign can hold multiple values, just like the Multi Select field in Gravity Forms.)

I have checked and triple-checked that both fields have an identical list of options. (Spelling capitalization, etc.)

However, after a form is submitted, Active Campaign only shows the first option. For example, if someone selects California and New Mexico in the form, Active Campaign only shows California.

Any ideas how to fix this?