I live in the PNW near Seattle, but because it is summertime, nighttime temperatures are consistently above 10 degrees celsius and daytime temperatures are around 27.
It started looking like this several months ago when it prepared to flower and it was still indoors for the winter. I put it outside and the condition kept deteriorating. The fruit also seems to not be getting any bigger.
About nine months ago when I planted it I filled the pot with potting soil and about two months ago my mum covered it with sand to keep water in or something. She raises a lot of houseplants so I assumed she was experienced on this matter.
I water it about every three days with about 250 ml water and a few drops of MiracleGro (it also occasionally rains). I read that to help iron deficiencies people put rusty nails into the soil so I stuck some old screws into the soil.
Is it the sand? I have a sneaking suspicion it is the sand.
I’m about as far away from you as it’s possible to be & still be in the Continental US, but a couple of things. Pineapple I hardly water at all, have it basically in orchid mix (my yard soil is atypical for Florida, very rich and damp) and they don’t absorb much through the roots so if you are trying to fertilize it or give it minerals, spraying diluted fertilizer on the leaves will work better than putting something in the soil.