I'm experiencing issues where some users visiting my website receive a "Your connection is not private" warning. The error suggests that attackers might be trying to steal information from my domain (e.g., passwords, messages, credit cards). This issue seems to occur with older browsers and devices, such as:

• IE 11 / Windows Phone 8.1: Server sent fatal alert: handshake_failure
• Safari 6 / iOS 6.0.1: Server sent fatal alert: handshake_failure
• Safari 7 / iOS 7.1: Server sent fatal alert: handshake_failure
• Safari 7 / OS X 10.9: Server sent fatal alert: handshake_failure
• Safari 8 / iOS 8.4: Server sent fatal alert: handshake_failure
• Safari 8 / OS X 10.10: Server sent fatal alert: handshake_failure Questions:

1. Is this issue caused by my hosting provider (Vercel) or something in my website's code?
2. What steps can I take to ensure these older browsers and devices don't encounter this problem?
3. How can I prevent the "Your connection is not private" warning for all users?

Thank you in advance!