Autoprovision Admin Password Set Fails

Has anyone had issues with setting the admin password for yealink phones via provisioning? I am testing with the latest firmware on t21, t48g and cp920 and they will not set the admin password after a factory reset of the phone. I confirmed the common cfg file is set with the correct format:
security.user_name.admin = {$admin_name}
security.user_password = {$admin_name}:{$admin_password}
which translates to:
security.user_name.admin = admin
security.user_password = admin:12345

I have also tried the newer configuration template that uses 'static' (but only for these two fields):
Code: = {$admin_name} = {$admin_name}:{$admin_password}
Setting the password works fine on other models (t29g, t42s, and t20 all work fine).

Scratching my head a bit and will open a ticket with yealink but thought I would ask here first.
I see the value being set for the admin password and I also see other values being set. I can update the phone's configuration on the fly via the device configuration in fusionpbx but the admin password is never being updated. I opened a ticket and will update when I get a response back.