Here's top Issues that slow down your Gmail, GDrive and how to deal with it
Network connectivity: Make sure you are connected to the Network (wire or wireless)
DNS: make sure you are not using a Public DNS at school for example: 22.214.171.124 and 126.96.36.199.
Service maintanance: ICT Dept. will infrom in case of Google Server Side issue
New protocol: Disable QUIC Protocol
1. Type chrome://flags in the address bar.
2. Search for the QUIC protocol
3. Select Disable
4. Click the relaunch now button (Bottom of screen)
Note: if you can browse any other Web Page but Gmail and Drive always blank like this
You need to access Gmail in Browser Incognito Windows (Ctrl + Shift + N) or go clear your browser cache to renew Data from Google
Bad Extensions: remove any unknown extensions in Chrome/Firefox
Then restart you Browser
If you are on Windows you need to remove any Malware by using Malwarebyte Software.
Download & install Malwarebytes -> Update Malwarebye database -> Scan -> Remove any Injected files/threat.