The cache encounters a false positive because, while the forms have different form signatures, both have the same source and target URL and form name (code). For some reason, the consequence is that no type predictions are displayed* -- I had expected them to be mixed up with the address type predictions. I haven't understood yet why.

This bug only concerns credit card forms since cache hits are ignored for non-credit-card forms.

*: Until you click into a field.

Payment form

Address form