FTV app requires reinstallation to work

[MSattler 390]

So I have a couple family members remotely using Fire TV Sticks.  So they install, they manually connect to the URL, the login page comes up, they select their username, enter their password, can connect and watch movies.  The issue is the next time they go use it, the login screen shows no pictures, if they select the user, and try the pwd they cannot connect.  I've been told if they delete the app and redownload it, it works again for that one time.  Is this perhaps a connectivity issue?  Should they try powercycling the ftv?

 

Thanks!

[ebr 16169]

The issue is the next time they go use it, the login screen shows no pictures, if they select the user, and try the pwd they cannot connect.  

 

Can you get an exact description of what actually happens here along with any messages they receive?  Thanks.