I can reproduce this with qualification: it only does this if you “cold start” the app while not having a data connection. In other words,…
if you don’t force-quit the app and you return to it without data connection, it will remain logged in a try (unsuccessfully) to access the cameras, or
If you force quit the app, but don’t try to launch it until you once again have data connection, it does not require login.
This is, I believe, because when the app cold starts, the first thing it does is check the current credentials. This is a security measure. If that fails it goes to the login page. This can be avoided by not launching the app from a cold start without internet.
Due to the security nature of this, my guess is that it’s not going to change. However, given the limited conditions in which it occurs, it really shouldn’t be much of an issue.
Also, by the way, the app does allow the use of iCloud Keychain for login credentials entry. So if you have your credentials stored in iCloud Keychain, you can enter them that way without having to type the password.