The Proton Pass web app should not sync the auto lock preferences with the extension.
Usually you want a short auto lock time for the extension, since it is used for shorts amounts of time (eg. filling or saving a password), but when you are using the web app you are usually doing something that may require more time (eg. editing a note, organising passwords ecc.), so you are forced to set a longer time for the auto lock every time you use the Web App, and if you forget to set it back you may have a less secure extension