Fog Server slow to respond during peak office hours.

We are running an internal Fog server with address 10.X.X.X and when we try logging into it between the hours of 8am-4pm, we are seeing sluggish response times. Ran wireshark and saw lots of SYN/ACK packets and at one point I see an RST packet then a RETRANSMISSION. I don't even know where to start to look. The reset packet, as well as all the others say Header Checksum: 0x0000 incorrect, should be...(different numbers). Maybe caused by IP Checksum offload. Does any of this help?

thank you RM

update: after looking at Fog server as src, noticed it was sending an RST with following attributes:

Length: 60, Port: random, Seq=1, Win=0, Len=0 (If that helps?)