Pasted image into existing PSD created with 20.0.7. New layer not visible until I transformed it. Found that copied layers were not visible until I clicked on their thumbnail.
Not seeing that an update has occurred but problem is not happening today. Checked multiple PSDs including much larger ones with large number of layers and all showed newly pasted and copied layers. Beginning to believe could be related to memory. I only have 16 GB and don't remember if I had other programs open while working on image.