In the latest update LoopIn & LoopOut expressions seem to be broken when I try to use them on time remap (as I always do when using a pre-comped loop in a longer comp). Getting weird glitches as if it is not obeying the end keyframe of the loop but rather playing the "last" frame of the precomp (i.e. a blank frame).
When you apply time remapping to a movie or a nested comp the last keyframe is always at the start of the first frame past the end frame. If you just the j and k keys to jump back and forth between the first and last keyframes, there will be nothing visible in the comp panel because that keyframe is the time one frame after the layer has ended.
You have to move back one frame (Ctrl/Cmnd + left arrow) so that there is something to see, set a new keyframe, then use the k key to move to the last keyframe and delete it for loopOut() to work properly. It has always been that way. If you just keep the original keyframes you will always get an empty frame at the start of each successive loop because that frame is empty.