#6 Custom alerts not expiring on 99xx phone

[bcstechnologies]

Custom alerts and screens that have been POST are not executing "go back" expiration on 99xx phones. The expiry works on 79xx. Normal GET screens expire just fine using same mechanism.
This appears to be a limitation in the Cisco 9971 firmware, and likely affects 9951 and some 89xx phones as well. Considering other mechanisms for expiring screens without using "Softkey:Exit"