The glass top had nothing to do with the failure of floating plants. Floating plants can get all the CO2 they need from air and since they are closest to your lights they get th most light. I have had the outflow from my filter push plants below the surface of the water and some got tangled up in decorations and submerged plants. None rotted away or died. Some actually did grow fully submerged. So if it if not CO2 or light or water on the leaves there is one one cause left. One or more of the 14 nutrients your plants need is missing. And your fertilizer is probably not providing enough of the nutrients that are deficient in your tank.I've never really had luck with floating plants, Though I was using a glass top, which I do not use now. I read that floating plants, do not like getting their leaves wet and can cause them to rot away.
Many fertilizers n the market have about 1 part per billion of zinc and copper or less. Which means most are deficient in copper and zinc. Fertilizers companies are essentially hopping your tap water provides all the the zinc and copper you need. Which means fertilizers work for some people and don't for others. Simply due to differences in tap water. Algae also does very well if a nutrient deficiency is present.
I cannot find enough information on line to know if this fertilizer has zinc or copper or how much is pressent. For my tank I had a lot of problems until I made my own fertilizer. Which is not simple to do. But in the UK there is one fertilizer that appears to be close to what I make.
Try TNC light. This would take care of your micronutrients.
As to your Macros nutrientsYou enough nitrogen right now and possibly phosphate for the plant. You can use your test kit to monitor nitrogen and you can buy phosphate tests. I would recommend yogurt a GH test kit to monitor you GH. GH is a measure of calcium and magnesium which are also macro nutrients..