I've got some troubleshooting tips here that may solve the problems you're having:
- Try using another browser
- Clear your browser's cookies
- Clear your browser's cache
- If possible, update to a newer version of your browser
- Restart your router
- Restart your computer/device
- If you're on a mobile device, turn off wifi then turn it back on
If this doesn't help, this may be an issue with the connection speed, so knowing what your upload and download speeds are will help narrow down the problem.