When you click ‘Constellation lines’, you will get a small pop-up window – make sure you check/click the ‘on’ box at the upper left corner of the pop-up, then click ok.  Otherwise you are just getting a current status of what is set (yours if apparently off) and if you just click OK, like you would think to do, it only closes the window – it doesn’t change any settings.

I make this mistake all the time….

Tony