Blocked websites on Safari
Public WiFi hotspots, especially free ones, tend to block certain sites just to limit bandwidth usage or potential liability issues. Workaround number one you have already found: use your own cellular data, which is not always an ideal situation.


VPN software is sometimes a good solution to this depending on if the public WiFi allows VPN connections. If it does you can get one that supports iOS (I use TorGuard but there are hundreds of others) and use that to bypass the limitations of some public WiFi hotspots.


Note: depending on what you are trying to do online that WiFi hotspot might see you sending and receiving large amounts of data (Netflix, YouTube, etc.) and block your MAC address and you are, again locked out of that particular WiFi hotspot.