Both Smitty and Ilda went through stages like that around a year and a half old.
I'm a big believer of putting the food down and leaving it down for 10 to 15 minutes and picking it up if they don't eat.
No emotions, no coaxing, no extra toppings, just quietly pick the bowl up and put food away until next meal time. They learn that if they don't eat food disappears!
The caveat being no other apparent health issues and since your already watching for that and going for a vet check you've got that covered.
So for now, I wouldn't worry about it.