Topic: 2h weapon Fallen Knight gets Reach Advantage stack if he bites during disarm

1. I’ve disarmed a Fallen Knight with a 2h weapon, he used the bite and after the end of his turn got a Reach Advantage stack

Sorry for not recording the bug or providing additional info, I hope it’s easy to check.
https://i.gyazo.com/1f53fab94b58e737514e7777d45a186c.jpg