I would firstly worry about your nitrates being zero. Plants will need some form of Nitrogen and if I'm remembering correctly it's one element that Flourish does not provide.
If the lighting worked in the past, and nothing has changed, I would not worry too much about that, but details would be an OK thing.. personally I prefer to control the light and only have the aquarium lit artifically, so I can control the amount and the time it is lit.. but if something changed, a tree grew, curtains were changed, or whatever that may have a bearing. Maybe share details of the artificial lights... it may be possible that bulbs could need to be changed.
Also pay attention to the amount of space taken in the substrate by the roots of the swords, In my experience they can get pretty darn big, and may just reach a point where there is no more room for them.
But honestly, I suspect your problem is the nitrates being 0, maybe try changing fertilizer to something more comprehensive, like Thrive or something like that.
If the lighting worked in the past, and nothing has changed, I would not worry too much about that, but details would be an OK thing.. personally I prefer to control the light and only have the aquarium lit artifically, so I can control the amount and the time it is lit.. but if something changed, a tree grew, curtains were changed, or whatever that may have a bearing. Maybe share details of the artificial lights... it may be possible that bulbs could need to be changed.
Also pay attention to the amount of space taken in the substrate by the roots of the swords, In my experience they can get pretty darn big, and may just reach a point where there is no more room for them.
But honestly, I suspect your problem is the nitrates being 0, maybe try changing fertilizer to something more comprehensive, like Thrive or something like that.