When I right click empty area in the track pane, I can't change the settings for “Set as default height” and “Lock Height”
They are set as stated below and will not change. Am I missing some master lock setting or something?

Set as default height... Highlighted (Tick on)
Lock Height… Greyed out (Tick off)
 

Sounds like you have "auto track zoom" on. Press Shift + Z or use the Track View Menu--->View to turn it off. Auto track zoom automatically opens the track to a preset (by you) height when the track is in focus.

Ha! Silly me! I can be such a daft ha’porth sometimes.
Thanks FBB