Thanks! I am running the same Firmware, however I am running the 2.46 Beta App currently in testing.
But, I replicated what you are experiencing on all four of my PanV3. They are not holding the Dark setting after exiting the cam and returning to the Home tab.
Since the next App update is in development, I will report this as a bug in the Beta Release thread for 2.46. Here is a link to where it was reported to be fixed in the next App release: