This is currently merged in the master branch. I am keeping the issue open for some more time in case any other external party needs to report/track the issue in their platforms/setup, I will then close if if no more occurrences of this are reported.
Needs Triage (15)
Fri, Apr 19
Patch for the ticket: https://review.trustedfirmware.org/c/trusted-firmware-m/+/789
The design document is posted to https://developer.trustedfirmware.org/w/tf_m/design/twin-cpu/general_mailbox_design/ and under review.
Thu, Apr 18
Wed, Apr 17
Anti-rollback protection: https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/887/
NV counter: https://review.trustedfirmware.org/#/c/trusted-firmware-m/+/886/
Patch for this issue is available here: https://review.trustedfirmware.org/c/trusted-firmware-m/+/881