Hotdesking phones not allowing sign in

[A_Criminal]

Hello, I've got a location that has quite a few Yealink T27G's that are having problems that we think might be provisioning related. All of the phones get no service and have a "Default password error". Changing the password gets rid of the password error, but it still gets no service.
We've tried turning off the trusted certificates only and manually provisioning it, and while that makes it appear normal upon reboot or attempting to log in to the phone it gets no service and the default password error again. It shows up in the admin side as logged in as the user when logging in, but does not display anything of the sort on the phone itself, calls cannot be made or received from them.

Has anyone seen this or have any ideas for a resolution?

 

[JohnS_3CX]

Hi,

We've tried turning off the trusted certificates only and manually provisioning it

We enable it upon provisioning for security purposes. If ity provisions the first time then the problem is likely your certificates.

1. Ensure they are running the supported firmware: https://www.3cx.com/docs/phone-firmwares/

2. If you use a custom FQDN you must use certificates that Yealink supports otherwise provisioning will not work.

3. If you are using an on premises install you need to have split DNS.