French Door Randomly Opens

I live in a fantastic house that was built in 1924. There are a set of French doors off of the living room that open into the foyer at the front door. The door to the right is locked in place and I’ve tested it, it’s not budging. Yet, periodically I’ll walk into the living room and see the door open with the deadbolt still engaged. This isn’t an issue of it not actually being shut or wind from either side. Can anyone explain to me what’s happening? It stops my heart each time it happens. I’ve never seen it happen, only come back into the room to see it open when it had just been shut.

I live in a fantastic house that was built in 1924. There are a set of French doors off of the living room that open into the foyer at the front door. The door to the right is locked in place and I’ve tested it, it’s not budging. Yet, periodically I’ll walk into the living room and see the door open with the deadbolt still engaged. This isn’t an issue of it not actually being shut or wind from either side. Can anyone explain to me what’s happening? It stops my heart each time it happens. I’ve never seen it happen, only come back into the room to see it open when it had just been shut.