Problem with Project Archive

Hello,

i have the following Problem:

I created a Backup of my Project in the Project Archive via "Backup to Archive". 

I see the Backup in the Archiv and my local Project shows me Green arrows.

When i open the local Project later again and ETS creates a Restore Point the local Project shows me Red Arrows and not as mentioned in the documentation blue arrows. It tells me, that the local Version and the Archive Version has changed and i have to create a Backup Copy. 

I dont understand this because i only changed the local project and not the Archive Version. Why i should create a Backup Copy?

When i create a new Backup in Archive then the Arrows went green. But when the next changes of the local Project came they went red.

Can someone tell me want went wrong or is this a Bug?