It looks like it got too dry, or got sunburned from a sudden increase in light, or the roots got overheated. If the pot is a dark color, &/or sitting on pavement, it would get hotter than a very light color pot and a cooler surface.

It’s in a terracotta pot, and it’s actually been in the same place for a whole year, getting direct light only in the morning. But there’s very less humidity right now and the temperatures are extremely high so what you’re suggesting could be true. I had kept a close eye on watering though, so the soil never really dried out.

Someone on another forum suggested pests, do you think that could also be a reason for these brown spots?

I don't see any pests, but it's possible.