Cannot reset QuickType suggestions

Hi.

I'm having trouble with QuickType suggesting a particular word, which isn't removed when I go to Settings -> General -> Reset -> Reset Keyboard Dictionary.

The word in question is the (unusual) name of an Airbnb host I contacted a few times several months ago. I never saved her name in my contacts.

When I go through the Keyboard Dictionary reset procedure above, and then open an app where I can type, the predictions appear be reset. But after waiting 30 seconds, re-opening the app, and then typing again, the string returns: the middle suggestion is 'Hi'; once I click on that, the host's name appears again as one of the three suggestions. It clearly is remembering the string 'Hi [name of host]'.

I never messaged this lady from my iPad, but the suggestion comes up there too - so it must be syncing through my Apple ID.

I'm not bothered about the name itself appearing in my suggestions, but it does trouble me that there is no way of resetting it and telling iOS to forget the suggestion. It's especially weird that the reset procedure has some effect at first - before iOS goes back to making the suggestion.

Is this a bug? And is there another way I can reset the predictions that QuickType makes?

Thank you very much.