[john70t]

It could be a single case of short downspouts and too much rain.
Or there might be a natural spring nearby. Should be a record of it with the city.

You can cut out a section of floor, dig a hole, liner and rocks, etc, install a sump pump if the water table every gets too high. That will help.

Grading and a surface water diversion barrier will also help.
I recently took a look at a beautiful wide property right at the end of long steep hill and turn-around. There was literally nowhere for water to continue downhill around the house. Everything funneled right into it. Yikes. A major flood would knock it right on down the hill.

The preferable way to seal it is from the outside and wrapped underneath....as a a giant reverse bathtub.
Most modern building practices do not address this basic flaw in foundation design.

Mom's former basement had continuous water dripping through a stairwell wall on the uphill side...even after weeks without rain. It trashed her new finished basement a couple times and left mold which probably shortened her husband's life. No problems at all from the decades before. There was either a natural spring or a major city pipe break uphill which the city didn't find or want to find. I was hollering and wanted to help. I was told to shut up and butt out. The house finally sold for a few hundred grand less than it was worth imo. It was a tiny little thing but otherwise in very good shape and located in the most expensive/highest-income area in the city. I would have hung onto it. Then my sister starts looking at properties here and they are all twice or quadruple that price. "Oh that's not a problem". Fffffffffffff. All the moldy cheese I was forced to eat growing up because mom wanted to save money.