This bug was discovered not so long ago by security experts from Bleeping Computer and, according to experts, has not been fixed. What is this bug? Typically, when you connect to a virtual private network (VPN), your device's operating system closes all existing Internet connections and then re-installs them through the VPN "tube".
However, in iOS version 13.3.1 and later, the operating system does not do this — that is, you can safely connect to a VPN, but other connections will also be active. This problem is also found in the latest version of iOS 13.4.
Most connections are short-lived and will eventually be re-established through the VPN tube. However, some of them work for a long time and can remain open for several minutes to several hours outside of the VPN connection. In particular, this applies to push notifications, which still go through an unencrypted channel when the VPN is active.
How to enable VPN encryption in iOS 13.4:
Step 1: Connect to your VPNA year and a half ago, independent experts conducted a study and found out that many VPNs from the App Store are actually insecure. If the service is American or european, then according to the laws adopted in US or EU, VPN providers must necessarily register with the state in order to be able to exercise supervision by the competent authorities. This, in turn, allows local authorities to perform all sorts of checks that involve analyzing user traffic passing through the provider's servers.
Step 2: Turn on airplane mode
Step 3: Turn off airplane mode