Hello,
that is very sad.
RealTime log data could be resetted when unit was turned off exactly when flight log was clearing. For example when memory was completely full it is doing clearing to allow new logs.
But we already found way how to resolve the issue and from new firmware 3.3.2 it should not happen even when clearing the logs anymore.
Unfortunately the issue related to Altitude Limit is resulting usually due to very high vibration level.
This page should help with the issue:
http://manual.spirit-system.com/index.p ... tion_driftAlternative possibility is when unit is changing collective pitch very hard, it can cause very big stress to mechanics. Can you check if some of push rod plastic was broken?
If one linkage or servo is not moving, it can look like when collective pitch was changed, either up or down, mostly in the highest available pitch.
In the Expert Settings there is Rescue - Smoothing Factor that might reduce stress noticeably. Value 1-3 can avoid this issue in the most cases. Default is 1 so probably it is already configured.
Your settings file can help a lot for finding possible issue.