Back from forest with dog, car locked, after 1 hour or so car alarm sounding.
Unlocked and locked from Kitchen lol as you do!
Alarm sounding again, so went outside and all 4 windows were full open!!!

Should I be Alarmed excuse the pun!

If the unlock button on the fob is pressed and held, all the windows will open. In the same way if the lock button on the remote is pressed and held all the windows will close. It’s possible that something in your pocket managed to press and hold the unlock button or if the keys were left at home something was put down on the fob to press the button. A bit like handbag dialling on a mobile phone.