I have noticed the same problem, primarily at work though. My assumption was that some of the IT-scripted policies had changed and cookies were being deleted more aggressively, although I suppose the Axiom site could be setting an earlier expiry date on the cookies.

Of course I went to look at a cookie to see and couldn't find any. Where does XP park them these days ?

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8