DFU OTA mcumgr slot 1 stuck (bad state 6)

[86s9f5w8]

Hi, I have issue where the slot 1 image seems stuck. It can not be erased, confirmed, or swapped in the state that it is currently on. When I click erase, the error bad state 6 will show. As per the error code, the source has this definition "The device is not currently in a state to handle the request.

This firmware image is thoroughly tested in production and has been working for 2 years. The version is stable and supports the SMP server version and implementation same as in the other version on slot 1 and slot 0.

Can the slot 1 still be recovered in some way?

nrf sdk v2.4.2
nrf device manager

[86s9f5w8]

Here is additional context.

As per another nrf5340 device the same flags are applied for another image. When I send confirm command the permanent changes to true so I believe this or the reset command is the last command sent to the device before it has got stuck.

zephyr 28a3fca7da5

first one point to the img_mgmt_erase which reads the info from the specified slot so i believe this fails causing it to check the the slot in secondary slot has flash confirmed or pending.

reset is not swapping the images either so does this mean the mcuboot is not swapping the images because of version downgrade protection or something. i have downgraded the device many times before so I don't know why it is issue this time. 

does confirm and test set some additional flags to check this version which would prevent it from downgrading? I know that nrf5340 does not support the mcumgr test command because of the multi core nature. Does it mean I can softbrick my device using this confirm and test command?