Answer:
interference
Step-by-step explanation:
The most likely reason for the connectivity problems is interference. This interference can be caused by many factors but in this scenario the most likely factor would be the metal studs and all the metal used to create the ceiling/floor. Metal is a huge interference when it comes to wifi signals. Depending on the type of metal and the amount it can greatly diminish the signal strength or even completely prevent the signal from passing to it's destination, regardless of how close the destination device is located.