this may sound like a odd question but it has been done,
have you done any water changes lately. I have even done this myself I forgot to mix in the salt to the ro
to put back into tank ,
another thought do you have a hydrometer to compare readings of both .
you say you get a reading 1.023 that still is in the safe zone ,
just remember raise the salinity slowly when you do get to that point so you don't shock the fish or coral