I have a banking app where I do not want LastPass to save my credentials.
I've tried blocking URLs and set "Do not show fill window" for the app.
It still opens autofill windows and ask me to save info.
Android Version 10.
Could you try first uninstalling the LastPass app, restarting your device, then reinstalling the app and going to the LastPass app Settings (at the bottom of the screen) > Autofill > App settings to make sure the app is excluded/removed? You may also need to select the "Do not show fill window" option again for that app.
Thanks for giving that a try. Are you able to go to the LastPass App Settings, Under App Fill, tap Edit fill helper settings, and then select or de-select individual apps by checking the boxes?