Week ago check salt cell light flasing. Followed the steps of Cleaning and added salt. Today took pool sample to pool store to be tested. Said salt was at 4000. When home checked the reading on swim pure plus box. It clicks on reads salt at 2200 then after a few minutes display goes to solid light on check salt and check cell. Took water and cell to pool place again. cell test working properly and salt test at 3900. Not sure what to do. Left salt system on off for 24 hours while pump ran. Cleaned filter. Put system back on auto salt reads 2200 for about a minute then generating clicks off and goes to solid light on check salt and check cell. Any help on next step would be appreciated!!