Upgrade 2.8 wont ring to caller on direct dial ext from IVR

Caller does not hear ringing when an extension is dialed from the IVR, the ext phone does ring ok, leading the caller to think something is wrong. It does work when the call is routed via the directory.

Do I need to set this somewhere. it worked ok on 2.7 before the upgrade to 2.8

Update: found it working and ringing to the caller this morning for a few calls but the minute I dialed an extension without Voicemail it stopped working.
I have reloaded, rebooted and searched everywhere and yet to find why. any troubleshooting hint is appreciated.