confused by punt block

A punt was blocked in overtime and recovered in the end zone by the team that punted. Then it gave him back the ball at the 20, with 2nd down???? Should that not have been a safty?



https://365.strat-o-matic.com/game/playbyplay/471436/75

I find it odd that there's no reference to a Ty Chandler fumble on the return, but since he was on the punt blocking team and recovered the blocked punt, it is within the realm of possibility that he recovered and possessed the ball in the field of play, and subsequently lost it, with the ball crossing the side or end lines in the end zone, resulting in a touchback.