It would be helpful to know what happens if instead of selecting the frame by clicking on the header with the frame numbers (like at 0:07) you clicked the cel that corresponds to frame 2 of the hair layer (or just pressed the right arrow on the keyboard with the hair layer selected). With that theme it’s hard to tell if clicking the frame number selects the whole range of cels for all layers at frame 2 (which would be new behaviour found in the beta) or it just looks that way and it’s the usual UI highlighting the X-Y intersection.
Hi @AnAfterImage, this transformation of multiple layers is made because you’ve clicked the frame (instead of just the cel). When a frame header is clicked, all layers from that frame will be transformed: