In my personal experience of owning these frogs; what Ived seen is that when they are babies they tend to be a little bit lazy. As they grow to max size they tend to be a bit more active. I think it maybe that they are trying to hide from predators? Also, you should provide alot of plants. I would get a fluval internal filter instead of a hang on back filter. I would put something to make the water movement slower. Like dont block the opening but put fake plants infront of it. This will "slow" down the water movement a bit. I fed my frog at random hours. I didnt want to keep a schedule. So it learnt that whenever I was around he should go look for food and maybe hed find some. As a baby I only fed it ONCE a day. He grew to 4inches I think within the year or two. It was a male. Yes these people are right these frogs are "community" frogs. Meaning they should be with another acf. But if you own two of these frogs as adults you WILL need a 20gallon tank. Personally Id go for a 40breeder because it gives them ample room for moving and you can add another, but you dont have to do that. I personally did that because I like seeing my frogs get comfy and swim about.
Maybe you dont have the heat up? If I remember their tank should be at about 82? I think 78-82 degrees. Don't use an overly strong bright light. Like one that would probably blind you if you stared at it from afar. These frogs have their eyes going upwards, so they see the light directly. That may bother them.
Dont feed blood worms btw. People will tell you to feed em blood worms and black worms and meal worms. DO not. Blood worms are very bad for these frogs, and meal worms cause impaction. As for black worms, I was told they arent that good but maybe someone else has their opinion on those? Provide a couple of hiding places. Try adding those fake lilly pads. They seem to like to hang underneath it sometimes. Once when I had mine as a baby it would sit in the lilly pad to rest for a few minutes. Then plop in the water.
Good luck. hopes this help.