My lions would eat every day.
Some take real special care to get eating. I had a dwarf zebra I fought with for months to switch him from ghost shrimp. It was costing upwards of $30 a month to feed him.
Try some silversides on a thread as Doug suggested in another thread. The idea is you want the lion to think the prey is alive. Once they start, they won't want to stop and you can hand feed them (carefully
).
Sometimes just feeding in the flow of a powerhead will work.
My dwarf fuzzy took live brine and I just starting mixing in mysis and larger pieces of seafood.
You really don't want to feed them freshwater fish as this inevitably leads to liver disease down the road.
Good luck.