protecting SSL server

Dears, 

I have a FortiGate device that is protecting multiple servers using deep inspection int the mode of protecting SSL server I have uploaded the server's certificate and pointed FG to use it to present it int the communications all is working fine except for one Centos server that as shown in the attachment I'm good in managing FortiGate however from the server-side I'm not sure.

the IT responsible for managing the servers assured me that he provided me with the right certificates, but something is missing.