FIXED: Host is not a tftp server

[hckeith]

Thanks for that tip mivk.

I used the TFTP client feature in Windows and tried to download a file. I'm seeing the request come into the TFTP server on FreePBX multiple times (with no errors), but I'm not getting the file back.

This could be why the phone is reporting that it's "not a TFTP server", as it's not getting anything back from its request. This is starting to look like it's a TFTP server issue on FreePBX rather than the phone.
I've further confirmed this by spinning up a FreePBX server as a VM at home and TFTP is working fine on this one with a Yealink handset.

I'll do some more investigating around that and report back with my findings in the hope it will help someone else out!