Yes, unfortunately it is not easy to fix in 4.1, sorry! 🙁 We have moved on to 4.2 and won't have more 4.1 releases.
The problem is that multiple keys get rounded in certain rare situations, causing them to be on the same frame. It can be seen by exporting to JSON, for example:
{ "time": 7.0333, "value": -0.06, "curve": "stepped" },
{ "time": 7.0333, "value": -0.06, "curve": "stepped" },
If one of these are removed from the JSON, then it will work correctly. Maybe you could write a script to find keys that have the same time and remove one.