Sudden change in two orchids, is it sunburn?

[AEKass]

I have had these two orchids for several (5+) years and have had them in the same spot (near south facing windows) for the past two years. Recently I noticed discoloration on both orchids. We typically keep our blinds up all the time, but since this was a sudden change and I have not changed their location, watering or feeding in years I am unsure. The weather has recently changed where I live (Chicago), but I have a humidifier that I use when it is very dry. I cut spikes off of both orchids within the last 2-3 months after all the flowers died. I water the plants by putting them under running water, putting the faucet in spray mode, and typically water in the morning. Based on similar posts on the message board I think this is sunburn, but I'm not totally sure. If it is sunburn, I'm unclear on why it suddenly happened and what to do going forward to keep my plants healthy.

In the larger orchid I noticed one side of its center suddenly became very light, as did a spot on one leaf. The discoloration seems to be worsening, but it is also producing a new leaf (just saw that today). The leaves also seem a bit parched.

In the smaller orchid, an older leaf was turning yellow and I wasn't concerned at first. However, recently several other older leaves (~4) have started turning yellow with some black spots. The black spots seem like sunburn, but I'm unsure. I took the photos of the smaller plant shortly after watering.

Appreciate any thoughts! And please let me know if I should provide more information or different photos. Thanks!