As it says in
the How-to Which of those two conditions do you have?
On to issue number two: low FC. If your SWG can't keep up with the demand, either it's failed or something is eating the chlorine it generates. If the cell is bubbling and there are no warning lights on the controller, it's almost certainly working. So something is destroying the chlorine.
Only two things consume free chlorine: Sunlight and organics. Organics includes, leaves, sweat, and dead skin cells. If your CYA level is adequate, you can rule out sunlight. But you can't test CYA with those strips.
Well then, how about running an overnight loss test? Oops, you can't do that, either.... the strips can't measure chlorine levels accurately enough. What if you start at 10. Is it 7, or 8, or 9 the next morning?
Now we're getting to the root problem. You need accurate test results and you need to know what they actually mean.
I suggest you spend some time in Pool School, particularly
the ABCs and everything on
the chemistry page. You could skip reading test kits compared and just go straight to tftestkits.net and get a TF100 ordered, along with some salt test strips. The other option is a K-2006 Taylor kit, which is hard to find in stock anywhere. They will try to sell you a K-2005 and tell you the DPD test is the same as the FAS-DPD test, but it's not.