2017.1 Mecanim issue

Hey guys I’m having a issue with our ThirdPersonTemplate Melee Combat only on 2017.1
We trigger a punch animation and it goes to a null state after completed, but only on 2017.1 this jitter happens:

@mecanimdev any suggestions?

It doesn’t look like any issue I saw before.
please log a bug and we will investigate

Thanks for replying, I tested on 5.5.1, 5.6.1, 2017.3 and 2018.1 and is working fine (same project) except on 2017.1 where the jitter happens.

The package is the MeleeCombat (Shooter also works): https://www.assetstore.unity3d.com/en/#!/content/44227

Here is a gif comparing:

5.5.1, 5.6.1, 2017.3 and 2018.1 smooth exit transition
https://gyazo.com/a020e103af66a002cdf1672c9dac133a

2017.1 jitter with same project, same animator, clean import:
https://gyazo.com/5f1e1cb68fc660c41687ceccc3164933

you should log it with the bug reporter because we can’t track bug listed on the forum.