You say typically.
Could someone have added a mtqq profile (it's a new feature in 13) to a virtual?
There are two possibilities - you are hitting something already known (in which case it may be easy identify from the config). However, the list of known tmm memory leaks into XDATA is quite short list.
Alternatively, you are hitting something completely new. In that case, Development need the core file and QKView to identify and isolate the issue.
Without providing data to F5 Support, all you can do is keep trying upgrades until the issue is fixed. If it is an unknown issue, it may never be fixed, because no-one else may have the same combination of traffic and config.