[dice]

Indoors to direct sun, that will damage leaves. I have
seen it before on other kinds of plants where I thought
it was going to be a cloudy day, moved them outside,
then left on some errand, and the sun came out before
I got back and stayed for the afternoon. The damage
was more extensive than what your plants are showing
(whole leaves all over the plant turned silver and eventually
died completely).

Misting or foliar feeding in them in direct sunlight can
do that, too.

That is not as unfortunate as an attack of disease or
signs of a severe mineral deficiency, though. The plant
will recover. At most it will slow it down a little bit until
more new leaves develop.