Moved my pepper outside, now it looks terrible. Any suggestions?

Photos: https://imgur.com/a/Eb1a0Gx

This is some kind of Italian (Calabrian) hot pepper, I think it's a diavolicchio but I'm not certain. I brought seeds from a plant in Italy but I started too late, so I moved the plant inside last autumn and moved it outside again last month. It has been outside for about a month now, and in the last two weeks has started looking less and less happy, and has lost a lot of leaves and some leaves have crispy edges. It's not over or underwatered, as far as I can tell. I don't see actual insects on it and I can't find any worms/caterpillars. I have a hard time believing this is sun damage because I live in Scotland. Any ideas?