I wouldn't say it's dying. It may be moisture stress though, my plant had that because I put my rockwool cube into the soil absolutely saturated with water, once I took it out, drained it, and repotted, my plant is coming back to life. I'm not saying to do that with yours because I am not fully convinced your plant has the same problem, I just want to illustrate that these plants are tough and can take a lot. Focus on how the new growth looks, while it's important to pay attention to Fan Leaves as well, if your new growth is coming in at a good rate and looks pretty good I wouldn't stress too much