[Support request] 5g fabric pots running too dry

This might be an EC issue because I’m used to feeding hard in a DTW system.
30 yr grower, 6 yrs in 70/30 coco/perlite running jacks nutes, pH 5.8, EC 2.4, dialed in vpd, 2000 drawn watts of LED, 1200 ppm co2.
This is my first run in 8 autopots/airdomes using a 60g res. I measured the depth of clay pebbles before adding substrate and plants to assure correct wicking action. they are on a level surface. The aqua valves are operating correctly but it has to be nearly dry before the vacuum break occurs to refill. The problem is new growth is beginning to show signs of underwatering and I need to dig 2″ deep before finding any moisture. I understand it may be dry on top, but either I’m not getting enough water or lack of daily flush at my current EC is beginning lockout. I couldn’t find a suggested EC, do you have one? Or any other suggestions? I really dont want to take a file to the vacuum break passage to keep float chamber more full.