I have been using the
gboard keyboard app for as long as I can remember. I also use password managers for nearly every situation, but they do not completely eliminate passwords. To my horror, gboard's predictive text feature recently started suggesting one of my passphrases. Specifically, if I wrote the first word of the passphrase, the next one would be suggested, and choosing that would suggest the next one after that, etc.
I force stopped the app and deleted both cache and app data. That did not fix it. So I went into settings and explicitly deleted learned words. That also did not fix it. So I looked for any situation where I may have (stupidly) typed it into an email. I could not find any example.
At this point, I am out of ideas for where Google may be acquiring this password. Obviously, I will change the password. But how do I keep this from happening again?