The OP’s problem may have been solved (or may have come back again in recent updates!) but as of early 2019, you can diagnose some of these problems by setting the show-autofill-type-predictions flag in chrome://flags, restarting Chrome, then looking at the title (tooltip text) for the input in question. It will tell you what information is being used to guess the “type” of field, and what kind of saved data should be used to populate it.