Export and Import Configuration ROS6

Hello,
I have a problem of this type with ROS6: If you export a configuration (export compact or simply exports in ROS v.6) to make some changes and then decide to reimport it I always get the result “Script file loaded successfullyfailure: Already have device with name longer available.”
This happens even if the changes are minor (for example change of a wpa key).
I also need to rename the interfaces and to do this with routeros 5.25 is sufficient to make an export, make the changes and then do an import of the configuration. Anything with ROS seems to be no longer possible.
I would like to proceed at this point exporting the configuration, resetting to default the hardware and then reimport it. But then I am afraid that is no longer possible to import it.
Anyone have any idea why happen only in version 6 routeros?

We also did this test on a RB951.
export config-> then reset system configuration (no default) → import
Same error.
Made the same test with the same device and ros5.25 and everything works properly.
It seems that somehow does not accept the configuration line on the bridge and the master port ethernet …
Can someone please help me understand?

has anyone encountered this problem? It 'a rather debilitating problem when using a backup to clone configuration on multiple devices.