Changing Extension SIP Driver

I have a strange issue and haven’t seen the question answered before.

FreePBX: 12.0.76
Asterisk 13.5

I have an extension that when i change the SIP driver from SIP to PJSIP and modify the ports on the phone config, all calls to this ext do right to voicemail. Outbound from the phone works fine so i know its registering correctly.

If i delete the ext and recreate it as PJSIP it works fine as well, but i would not want to recreate all of my ext’s

Any thoughts?