Is this a bug of `doveadm mailbox metadata set` with `-A` and `-s ""`

Dear all,

Recently i encountered an issue with doveadm mailbox metadata set (and unset) with either -A or -F <path>.

When i run doveadm mailbox metadata set for single user, it correctly generates content in dovecot-attributes file:

doveadm mailbox metadata set -u <email> -s "" "/private/vendor/vendor.dovecot/http-notify" "user=all"

But if i run with -A, or -F <path>, Dovecot generates incorrect "path" and unreadable characters in dovecot-attributes file:

# doveadm mailbox metadata set -A -s "" "/private/vendor/vendor.dovecot/http-notify" "user=all"
# for i in $(find . -name 'dovecot-attributes'); do echo $i; cat $i; done

priv/4898662293abe1690d9a000063130d18/vendor/vendor.dovecot/pvt/server/??????
user=all
priv/90e7b40fc8c1e9690924000063130d18/vendor/vendor.dovecot/pvt/server/vendor/vendor.dovecot/http-notify
user=all
priv/60ba353790c1e969f923000063130d18/vendor/vendor.dovecot/pvt/server/endor.dovecot/pvt/server/CV??
user=all

It's ok if i specify the mailbox in -s, for example: -s "INBOX", -s "Sent", but it's not what i want, because only emails delivered to specified mailbox will be pushed.

Is this a bug?