I'll preface this by saying that I use a 3rd-party password manager (RoboForm Everywhere). Some of the issues seem to be with that service and some are with the Google feature itself. Roboform IS updated to support this feature, it's an option in the settings.
In short, it just does not work. With the impending shutdown of using accessibility services to autofill passwords, I figured I'd give the new feature a try. On 3 of my apps (Key Bank, Citi Mobile and Chase Mobile), I am not able to even get the opportunity to auto-fill a password. On a fourth (Time Warner Cable's MyTWC app) I can get the auto fill option but then it reports contents couldn't be auto filled. I believe 3 of the 4 apps have been updated since Oreo was released, this should work.
Total. Fail. IMO...
In short, it just does not work. With the impending shutdown of using accessibility services to autofill passwords, I figured I'd give the new feature a try. On 3 of my apps (Key Bank, Citi Mobile and Chase Mobile), I am not able to even get the opportunity to auto-fill a password. On a fourth (Time Warner Cable's MyTWC app) I can get the auto fill option but then it reports contents couldn't be auto filled. I believe 3 of the 4 apps have been updated since Oreo was released, this should work.
Total. Fail. IMO...