How to make a Firestore quarry that filters for two fields?

Hey, may I ask you a question on the geohash thing? I tried it for multiple hours but I can't figure out how the hashes get indexed. If I set the hash of the lower left corner of my rectangle as "start at" and the right upper corner as end at, doesn't he list everything, that is inside of the whole ring all around the globe? Or does he realy only check the hases inside of the rectangle? I tried it with any possible corner combination but it will Sometimes give me documents even if there have not been any in the square and sometimes It doesn't returns me any documents even if there are some in the square. I also cheked my hases on a website and they get generated correctly.

/r/Firebase Thread Parent