Check the GE, The handles are not flat between the 2 keys.
How can you spot this from the action editor?
Look at the bars between all the keyframes. If there is a ‘bar’ that seems to connect between all the keys it means the value is constant. EG – it looks like the Scale keys are always at 1.0 so all the keys look connected.
Hope that makes sense.
Let me know if it solves your issue.