Error when working as an anonymous user in versions 2.6.2, 2.7.1

[ihard]

After updating to 2.7.1 or 2.6.2 - the ability to work under an anonymous user disappeared (x-webauth-user is empty)
on version moira/web2:2.5.1.0 or moira/web2-nightly:2021-10-25.3a13f8c the error is the same
"Invalid request: user not permitted to use contact" - when trying to add a new contact and subscription.

[ihard]

workaround: set x-webauth-user and copy contact and subscription то this user