Instant replay hanging for 3-4 seconds

[tpw]

Since build 1028 I've noticed that every time I hit the R key for instant replay, the replay plays for 5-10 seconds, then the visuals freeze for 3-4 seconds. The sound keeps going though, and eventually the visuals resume at the caught up car position and the rest of the replay continues without issues. Once the replay finishes I can hit R again immediately and it will play without hanging.

I've tried changing the replay fidelity settings in-game, and the replay compression settings in the player.json, nothing seems to make any difference.

Anyone else seen this or have any ideas?