https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929131 >> The penetration loss through multiple layers was observed to be as high as 47.6 dB for I2I scenario, yet not as high as the 66.5 dB observed for the O2I scenario. In summary, we conclude that signals transmitted at 60 GHz both inside buildings and into buildings will suffer from severe penetration losses due to ambient building materials, heavily reducing coverage with respect to line-of-sight conditions. On the other hand, the high penetration loss of building materials can be a potential advantage to reduce interference from neighboring wireless network systems. 47db loss is basically unusable especially with low power devices like a phone or wifi aps which are limited to around 32db of signal strength. You aren't getting fullband 5g inside your house they are reducing frequency to 24ghz extended range 5g in those conditions regardless of what your phone displays.