The tracking tab stays hidden until 1 read/delivery receipt/voting response
comes back. (keep in mind that read/delivery receipts can be suppressed by
the recipient or recipients mail server.)
I am not entirely sure the information you provided is accurate? I too am
encountering issues with the 'tracking tab'. I noticed today however that
while I did receive a 'DELIVERED' receipt for a particular email, I still
dont see a tracking tab if I go into the original email in my SENT folder
.......?