MacBook Pro on any wifi stays connected but won't load pages after a few minutes
I had faced same. Sometimes cable connected to wifi card becomes loose which can cause this issue.

Can you check once what RSSI you are getting when you are scanning the the Wi-Fi network? Usually macOS at -70 dBm RSSI shows very less connectivity but windows works fine.


Click on "Apple" icon.
Select "About the mac"
One window will pop-up then select "System Report"
One another window will pop-up. Select "Wi-Fi" under "Network" option.


you will get all the network list. All the scanned network will have a field "Signal/Noise", where you will get your RSSI value.