Hi [NAME],   To disable KEX? - I think a command syntax of '#no ip ssh server kex' should disable KEX.    Also, could you check if you're running on firmware 9.10? If yes, please update to 9.14.1.8. 
Our security tool alerted about week KEX algorithims enabled on the FN410S I/O module one of our non-prod servers has.I've been trying to figure out how to disable it but can't seem to run the command. I entered conf mode, but my only options under ip ssh server are enable and version. show ip ssh shows that the diffie hellman methods are enabled. I have been referencing CLI documentation [URL] but can't seem to get the KEX portion to run. Does anybody have example syntax for modifying the KEX value?
Dell FN410s SSH Key Exchange