Memory leak?

I have this weird issue… I was sitting next to one of my Cisco phones and the LED message indicator came on. The phone did not ring and neither did any of the others, but a message appeared.

I checked on my settings as I have an after hours ring group set up, it was not the problem but I noticed my app memory was at 86%. This is very abnormal for my system as it normally sits at around 25%.

After a reboot, everything returns to normal, phones ring and I can use it ok. If I leave it and watch it, I can watch the App Memory increase in size until the system gets to about 85% and all calls go direct to voicemail again.

I have made no changes to the system, but installing the normal updates via Module Admin.

Any Ideas?

FreePBX Framework is
Asterisk Ver
All modules up to date.