I have the same issue when I toggle obscureText the autofill disapear and come back. Its very annoying. For me the problem seems to be ios 18 I tried wth real device and emulators on ios 18 and the problem persist. It does'nt bug on ios previous 18. Based on my research there a lot of bug related to the keyboard on ios 18. I haven't found a solution yet. You can probably make your own obscure text fonction and keep the textformfield parameter to false.This is not the exact problem but its seem similar https://github.com/flutter/flutter/issues/162173