Android Chrome won't use 1Password, only Google Password Manager

Thanks for the help. I've deleted all passwords from Google (labourious process without a delete all) and it made no difference (although I needed to do it anyway). Eventually, I found a special setting under the "Google->Autofill" settings that gives Chrome special override access over your actual Android configured auto-fill provider. Switching off the special "spuriously ignore autofill settings not set to Google" setting does the trick. It might be worth mentioning in the docs, although the setting is actually called "Use Auto-Fill with Google". Completely unnecessary as the main published auto-fill provider setting allows you choose Google. This is just a rear-guard action to make the public auto-fill provider selection ineffective.