Hi Dinky
I had same issues with my ACF's,.the general advivce might be to slowly introduce
New food to frogs, the pellets might be new to him and you might not be aware of
What he was eating previous( can you ask)
Introduce as much frozen food(ensure thawed before fed) ie shrimp & worm types
Do not give to much blood worms or beefheart both are thought to lead bloating.
Keep trying pellets but remove whats not been eatin after 15 mins

Dried food other than pellets ie worm are ok for quickness or shortages with frozen
but contain 40% less nutrient