auto fill in gmail app isn't working correctly

[Android Central Question]

I have tried in 2 samsung devices and the auto fill isn't working correctly, it has forgot some email addresses that it used to know, this is driving me crazy, my pc gmail account works fine, it is only happening in the app.
i have now opened gmail through chrome on my device and this has saved me, so i want to know why is the gmail app doing this, I have read through a similar thread and done what was suggested, but still this issue is here?