After looking at the server log it does not seem to be a server issue. All issues were reported on the 12th of december:
2018/12/20 14:54:50 [error] 9919#9919: *233 directory index of "/var/www/seekadventure.net/" is forbidden, client: 76.176.176.95, server: www.seekadventure.net, reques$
2018/12/20 14:54:53 [error] 9919#9919: *233 directory index of "/var/www/seekadventure.net/" is forbidden, client: 76.176.176.95, server: www.seekadventure.net, reques$
2018/12/20 14:54:54 [error] 9919#9919: *233 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 76.176.176.95, server$
2018/12/20 14:54:55 [error] 9919#9919: *233 directory index of "/var/www/seekadventure.net/" is forbidden, client: 76.176.176.95, server: www.seekadventure.net, reques$
2018/12/20 14:54:56 [error] 9919#9919: *233 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 76.176.176.95, server$
2018/12/20 14:55:35 [error] 9919#9919: *233 directory index of "/var/www/seekadventure.net/" is forbidden, client: 76.176.176.95, server: www.seekadventure.net, reques$
2018/12/20 14:55:36 [error] 9919#9919: *233 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 76.176.176.95, server$
2018/12/21 01:47:26 [error] 9919#9919: *261 directory index of "/var/www/seekadventure.net/" is forbidden, client: 76.176.176.95, server: www.seekadventure.net, reques$
2018/12/21 01:47:27 [error] 9919#9919: *261 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 76.176.176.95, server$
2018/12/21 01:47:32 [error] 9919#9919: *261 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 76.176.176.95, server$
2018/12/21 01:48:36 [error] 9919#9919: *261 directory index of "/var/www/seekadventure.net/" is forbidden, client: 76.176.176.95, server: www.seekadventure.net, reques$
2018/12/21 01:48:53 [error] 9919#9919: *261 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 76.176.176.95, server$
2018/12/21 01:50:10 [error] 9919#9919: *270 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 66.249.66.135, server$