What food are you giving him? You might want to give him more % of the RC in the RC-Weruva mix. Test every 30 mins when he is in the 50s, especially early in the cycle.
Normal mixture would work out to what carb% approximately? When you get such a drop early in the cycle - especially to low green - you want to feed higher carbs to slow him down.
If he drops below 50 or lower, what should we give him. We still have Royal Canin E which is 27% carb and his old food Hills K/D which is very high at 38%