pool member not responding to https port (443) but responding on tcp.

could you please help me with the tcpdump command, and what i need to check from that tcpdump.

try this and look for tcp reset or http response which does not match the receive string.

 tcpdump -nni 0.0:nnn -s0 -w /var/tmp/output.pcap host x.x.x.x and host y.y.y.y and port zzz -v
x.x.x.x is non-floating self ip on server vlan
y.y.y.y is server ip
zzz is server port