Sporadic redirect to homeURL after login

[egobrc at gmail.com]

Hi,
on my Service Provider I noticed that sometimes, after a successful
login on the IdP, the user is redirected to "homeURL" URL (the
attribute is described here:
https://wiki.shibboleth.net/confluence/display/SP3/ApplicationDefaults
) instead of being redirected to the correct application page.
Sadly this issue happens about one time every 20 logins, it is very
sporadic and I was not able to reproduce it systematically.

Do you have any clue? Or any suggestion to debug this problem? I
searched in Shibboleth log files but I did not find any specific
error.

Thank you