The Aweber integration is a different set-up from other autoresponders. You'll notice that Aweber does not ask for an API Key, instead we save a cookie (information you save, eg. login details), and whenever you clear your cache, cookies saved area is also cleared. Since that cookie is saved for that specific computer, if you attempt to connect through an Incognito browser, clear cache, or a different computer, Aweber will ask for the credentials because the cookie isn't saved. Unfortunately, it's not something that we can control on our end.