Some of the 'Add Shape' tools such as 'Add Closed Shape', 'Add Open Shape', 'Add Shape Rectangle', 'Add Shape Circle' etc. don't use the currently selected / last used layer. Instead they appear to always switch back to a default. In my case this is the Solder Mask layer.
If you select one of the above tools then use 'Change Layer', the new layer is not saved so that the next time you use any of the above tools, the layer reverts back to the default. This is REALLY frustrating and annoying when trying to add shapes to the Bottom Copper layer!
Other tools such as 'Add Copper Closed Shape', 'Add Track' etc. use the currently selected layer which gets saved when it's changed.
It appears that if you change the layer using 'Next Layer' rather than 'Change Layer', then the new layer IS remembered by the tools referred to above. Surely this is a bug in the 'Change Layer' functionality?
BTW 'Next Layer' is not at all useful because you cannot tell which layer is current either before or after clicking 'Next Layer'.
The best analogy is having a box of pens with different coloured ink but all the pens look identical. You don't know which ink you are using until you put pen to paper and start to draw. 'Next Layer' is equivalent to picking another pen from the box - you still don't know the ink colour of the next pen.
Why can't we have a permanently displayed indication of the currently selected layer?