Of course there are exceptions.
Kmuda has an Oscar that develops pitting if salt is discontinued.
If there is sufficient tank space and filtration, and the water quality is maintained with frequent water changes, it usually is not required.
I would stop using it and see what happens.
If you see fin rot, first ensure all your other standard parameters (ammonia/nitrite/nitrate) are OK.
If your PH is stable anywhere between 6 and 8 is no problem.
Far more damage is done by attempting to change PH than by it being off some imaginary number.
My PH is 7.4 to 7.6 and I've kept Africans and SA cichlids with no apparent issues.
If they all check out, see if it improves by adding salt again.
Fin rot is usually a water quality issue.