Website Returns 521 Error (OpenSSL/1.1.0g) Issue

I’ve been trying to get SSL running on my domain. I believe I have Apache set up properly and installed Lets Encrypt using DO’s official tutorial. Before the websiter is working correctly with http and https requests but now i everytime get sich kind of 521 error (web servber is down): http://prntscr.com/mmpehl

Also I check all ports and here is the info: http://prntscr.com/mmp9c6 Also I cehck the log and see this:

[Mon Feb 18 06:25:05.241057 2019] [mpm_prefork:notice] [pid 17889] AH00163: Apache/2.4.29 (Ubuntu) OpenSSL/1.1.0g configured – resuming normal operations [Mon Feb 18 06:25:05.241126 2019] [core:notice] [pid 17889] AH00094: Command line: ‘/usr/sbin/apache2’ [Mon Feb 18 06:41:57.739447 2019] [mpm_prefork:notice] [pid 17889] AH00169: caught SIGTERM, shutting down [Mon Feb 18 06:41:57.923695 2019] [mpm_prefork:notice] [pid 26327] AH00163: Apache/2.4.29 (Ubuntu) OpenSSL/1.1.0g configured – resuming normal operations [Mon Feb 18 06:41:57.923795 2019] [core:notice] [pid 26327] AH00094: Command line: ‘/usr/sbin/apache2’ [Mon Feb 18 07:38:40.007136 2019] [mpm_prefork:notice] [pid 26327] AH00169: caught SIGTERM, shutting down [Mon Feb 18 07:38:40.182897 2019] [mpm_prefork:notice] [pid 27472] AH00163: Apache/2.4.29 (Ubuntu) OpenSSL/1.1.0g configured – resuming normal operations [Mon Feb 18 07:38:40.182996 2019] [core:notice] [pid 27472] AH00094: Command line: ‘/usr/sbin/apache2’

If you can help me understand what needs to be done to fix this issue I would greatly appreciate it.

Maybe something wrong with files from this directory: /etc/apache2/sites-available/ ?

Thank in advance.