Uptime says that site is down, but it's not

Uptime says that my site is down for 2d 1h 22m and shows the following error
Error: write EPROTO 139813891807040:error:14077410:SSL routines:SSL23_GET_SERVER_HELLO:sslv3 alert handshake failure:../deps/openssl/openssl/ssl/s23_clnt.c:802:

But my site is working fine. What is the cause?