Brownish yellow spots on monstera

Question

Spots have developed on the leaves of my monstera deliciosa, and I've found nothing online that's quite like it. It's not on top of the leaf, can't be wiped off, and it's not growing in regular circles like rust. It's irregular tan/brown spots looking translucent and yellow with the light from behind.

I noticed it on one leaf when it was about as bad as the leaf in the picture, one other leaf had some spots at the time too. Over the last two weeks the first leaf hasn't changed while the second has become as bad as the first, and I now see flecks of it on one or two other leaves on the same stem.

(The white dots are dust, I see nothing at all moving on the leaf.)

I live in Sweden, the plant is a year and a half old, I repotted it a month ago and it's close enough to a south facing window that a few leaves get a few hours of direct sunlight, not usually the leaves in question though.

It's mostly affecting the leaves of one of the smaller stems, so if there's no treatment I'm considering cutting that stem and propagating it to it's own pot.

Thanks for any tips or advice.

Answer 1

I believe it might be nutrient deficiency. This is what I have been told from someone who had a similar looking problem, and I haven't added fertilizer since before repotting so it makes sense.

I will start fertilizing again and report back on the progress in 2-3 weeks.

Edit: The two leaves kept worsening for a while, but they have not changed during the last week and a half now. If it worsens again I'll update the answer again.