Mysterious Puddle in Living Room

A small puddle of water appeared suddenly in my living room. I wiped the area but two days later it appeared again. I live on the first floor of a two story building but the upstairs owners are seasonal and their main water is shut off when they're not home. The home was built in 2017. There are bathrooms on either side of where I noticed the pool of water. A leak inspector's analysis says that there is no leak in either bathroom but he heard water underneath the floors. I live in south Florida and when I noticed the water it had been raining torrentially for several days. A plumber will be here soon to fix the issue but I'm confused because it's been over two weeks since the water appeared and it has not happened again since. Do you have any idea of what's going on?