I am a new purchaser of Affinity Photo and have been working through your Affinity Photo Workbook. On page 126 entitled "Further Manipulating Layers", the locking of layers has no effect. I can move them, group them, rename them and change parameters without restriction while layers are locked.
Affinity Photo version 1.6.5.135
Windows 10 Home, version 1809, OS build 17763.316
File name: layers_naming_locking.afphoto
Thanks.