Q.Indoor Plant Issues
I’m starting to see leaf issues with 3 different plants. The first two are near a windowsill that doesn’t get much direct sun and the last photo is a plant that gets no sun.

Certified GKH Gardening Expert
The middle one may be suffering from improver watering or humidity, which usually results in brown leaf edges and tips. The one without light may be having trouble with photosynthesis; see if you can move it to an east or south window, or add a grow light. Most indoor plants prefer bright, indirect light. Even the ones that are promoted as low light seeking, really prefer brighter light but will tolerate low light levels. The blotchy plant, however, may be getting too much direct sun and needs to come further from the window.
https://www.gardeningknowhow.com/plant-problems/environmental/plant-leaves-turn-yellow.htm
https://www.gardeningknowhow.com/houseplants/hpgen/windowless-houseplants.htm
https://www.gardeningknowhow.com/houseplants/hpgen/houseplant-placement.htm