HDR sky not rendering unless I resend entire scene

[itaki]

So, this hasn't happened to me before, but now every time I make the slightest move or change the model rerenders in the viewer fine, but the HDRi environment disappears and the only way I can get it back is to resend the whole seen manually to the viewer. Then I make another change and it disappears again. Anybody experience the same problem? Think it might have something to do with scale but not sure.