Wood swelling

I have become wary of using mitered corners around solid wood panels without using any reinforcment like a keyed miter. If you wanted to use the same woods again I would try slotting the miters and gluing in a couple of keys from the same speices wood. I have had very good experiences using this technique in the past.

-- Do or do not...there is no try - Master Yoda

Any time you wrap a mitered frame around a solid wood panel, you are playing Russian roulette.

If the panel is sealed on both sides, that will limit moisture absorption and thus reduce movement. If the piece is kept in a temperature and humidity controlled environment, that will also decrease the chance of problems. Miter keys, as woodenwarrior suggested will also prevent the corners from separating sometimes.

But none of those will guarantee you won’t have a problem. That’s why your option #2 is the go-to solution when you want the framed-panel look.

-- Charlie M. "Woodworking - patience = firewood"

OK this all makes sense now. I should have at least sealed the core before wraping it and reinforced the corners with keys but best practiace would have been to use a solid core with vineere.