How much direct sun was it getting and how long? Even outside they can handle some morning sun but will burn in midday sun; inside I suppose this can happen if it were directly in front of a really sunny window. Otherwise, they really are easy palms, so something is really wrong here. Don't think it is water related.

1.Sunlight indoors usually drops the humidity to desert levels- the fronds can't keep up.

2.THEN,the other possibility is- it was in too dark,too cool, a situation at the store..and being watered too much its rotting the roots. Save the receipt.

Looks like sun burn to me, or some sort of burn (sometimes fertilizer burn can look like that, too). You fertilize it recently? Still, sun burn is extremely common with palms that get moved out into sun, even if eventually they can tolerate the sun just fine.

Hi all, thanks for your replies. The first few days I placed it near a sunny window which gets morning sun, not sure how many hours though. I feared sunburn so I moved it to another place in the living room where it doesn't get any direct sunlight.

I'm starting to suspect it has something to do with humidity as pointed by stanofh. It has been a couple of warm days here in Portugal and humidity by the window probably drops to desert levels. I'll try to spray it with some water to create some mist.

Do you feel I should move it again close to the window? In the store it was placed outdoors on a quite shady place, so probably better keeping it in the shade?

thank you!