Moving back from 18.5 MR1 to 19 EAP1 - Configuration are lost

Did you migrate or did you simply boot on EAP1? 

If you "go back" in the Firmware, the firmware on the inactive slot will freeze and not be used. If you boot again this version, it will move to the other slot, but not migrate the configuration. You would need to upload a firmware and migrate the existing configuration. 

So, I need to upload the 19 EAP file in order to get the cconfiguration update? Really?

That is how the system worked for 7 years? Each slots are working independently.

I would say 6 years, LuCar. XG 15 was released in august. So, what is the useful case to have these 2 things separately? What is the goal to have a swap version, if you cannot bring the configuration too? To test if everything is working, without impacting the current configuration? How can you test something if you do not have the configuration? Please explain the use case scenarios.

I would say 6 years, LuCar. XG 15 was released in august. So, what is the useful case to have these 2 things separately? What is the goal to have a swap version, if you cannot bring the configuration too? To test if everything is working, without impacting the current configuration? How can you test something if you do not have the configuration? Please explain the use case scenarios.

You actually did not use the use case, most customer use. 

So lets point out the impacted customers: 

You are coming from MR1 to EAP1 --> Migration will be migrated. 

You notice a issue, go back to MR1. --> Migration will not be present. The MR1 version, which was freezed will be activated.

You decide to stay on MR1 and work on MR1. --> If you would give it another try: Either way you upload the "New MR Version" or the same version, you already tried to try it again. Most likely customer at this point will wait for new release. 

To look at those "If´s", the impacted customers are marginal. 

Ok, clear. My case was: from 18.5 MR1 -> MR2 -> MR1 -> 19 -> MR1 -> 19.

In the last migration, I lost the configuration I did on MR1.

You could enter the migration steps as well. I highly doubt, there was a migration. There was simply a reload of the state, which was frozen. It is like a snapshot. 

Ok, understood. I will try to upgrade to EAP again and see if everything is there. Thanks LuCar.