Hi, We are using 3cx v15.5 with Cisco SPA 504G phones. The phones had been working fine with the previous version we used, that is v12.5 but ever since the upgrade DND feature doesn't get turned off in some of these phones. When we press DND, it dials *32 and informs that "out of office is set", but when we try to turn off the feature by pressing DND again, it doesn't dial *30 instead if dials *32 and plays the same message back again. Has anyone encountered the same issue? Is there any fix for the issue? Thankyou.