Hi @Andy1P, thanks for confirming that for us.
The Autofill menu displays items that match the field type only. So if you tap "Open 1Password" from a sign in field, only Login items will display. If you do the same in a credit card field, only Credit Card items will display. As your wifi sign ininformation was saved as a Wireless Router, it won't be presented here. I'll also note that 1Password for Android cannot fill Wireless Router items.
I would suggest saving your wifi sign information in a Login item then linking it to your Wireless Router item to help keep them organized. Thanks again!