My efficient angler seasonal challenge is unable to progress past 16/25, and has been stuck since near the start of the season & preventing me from getting the Aquanaut title.
I've tried different ponds, using different subclasses, completing the event and attempting again once the pond is back, maxing out the pond from 0 meter, joining a pond already at max, but the challenge remains stuck at 16/25 fish caught at max catch bonus.
Bungie are aware of it and are still investigating it.
Wouldn't be surprised if they end up just giving progress to everyone or changing the requirement before the season ends.