Jackfruit leaves discoloration

[EmuBrain]

Year-old jackfruit plant. Never been fertilized.

Looks like the leaves are turning yellowish, then turning white from the tip, then going around the edges and protruding inwards, starting with the youngest ones.
Trying to diagnose my plant, I find that a lot of sources say different things. Right now I'm leaning towards a potassium deficiency or maybe iron?, but this could be entirely wrong.
Could also be a light issue, as the symptoms started when the sun started appearing after a tough winter (standing indoors). But the plant stands near a window with not a lot of light and hasn't been an issue before, nor have the other plants.
The plant is not overwatered. I only water when the soil is really dry, and the leaves are just starting to wilt.

Any thoughts?

https://imgur.com/a/mpJ40mf

 

[YumYum]

The pH of the soil may be getting out of range of what the plant likes. Likely from using well water or city water and over time it changes the pH of the soil. That would be the first thing to check.

 

[EmuBrain]

The pH of the soil may be getting out of range of what the plant likes. Likely from using well water or city water and over time it changes the pH of the soil. That would be the first thing to check.

Great suggestion. Sadly it seems fine however. Measured it to be around 6.5 in ph which should be acceptable.

 

[YumYum]

Try giving it some fertilizer with iron.