I cannot remove the inline Frog cartridge holder from our Caldera Kauai spa. In the past, to change the bromine and mineral cartridges, I first unscrew the cap and set it aside. I then press down and turn anti-clockwise the cartridge holder and it releases and comes out. I can then remove the old cartridges and replace them with new cartridges. I then put the cartridge holder back in the spa, line up the arrows and turn clockwise to lock it in place. I then screw the cap back on. Today, I am still able to unscrew the cap and set it aside. But when I press down on the cartridge holder nothing happens. It is stuck. How can I get it unstuck? It has worked fine for 5 years. This is the first time I have not been able to remove the cartridge holder. The jets are off when I do this activity.
