There is a big difference with the duration and intensity of direct sun on an outdoors deck compared to some afternoon sun through a window indoors. The plants were simply not ready for that much sunlight all at once. They need to be acclimated slowly and the peace lily and elephant ears are never going to be happy in all day sun anyway. They are both low light plants and want more shade than sun.

never.. i mean NEVER .. move a houseplant out into full sun.. without hardening it off for at least a few weeks ...

you sunburned the leaves so bad.. they fell off the plant ...

if you can maintain proper watering..and the plant was otherwise healthy.. if should releaf.. and new leaves that come out in full sun.. will be accustomed to said full sun ...

ken