it happens with apps that are a bit unstable sometimes that the app data cache gets out of order or too big or many other issues, it's separate from the ccredentials and configuration, it's just a working storage area

for future reference, you long-touch the app launch icon and select the "App Info" menu item and in "Storage and Cache" there is a button "Clear cache" which will do it without the rigmerole of uninstall/reinstall/login