With no suggestions, I ran the numbers on the aircraft CG calculator, which offer a 3" from LE CG for 15% static margin, 3.5" for 10% and 4" for 5%. Instructions call for 3.75" and I'm currently at 3 5/8" so, I'm thinking that the tail plane is settling with loss of stabilizer grip at slower speeds and causing the ballooning and will move the CG forward a bit to see if that stops it and desensitizes the elevator a bit.