APM Access Profile inserting characters into page source?!
I am working on configuring SSO into as many applications as possible. We have an access profile setup that requires forms based authentication from a user, and then uses NTLM to SSO into apps. I recently ran into a bizarre issue with one of our applications. As soon as I configure an Access Profile for one of our LTM virtual servers, it changes the page source for every page, inserting 4 characters at the top of the page:
It also inserts a 0 at the bottom of the page:
If I remove the access profile, so it is just an LTM virtual server (SSL Offload, HTTP iApp Configuration), it seems to work just fine:
We're not doing anything with connectivity profiles, rewriting, or patching in APM. Has anyone seen this before, or know what causes it? Even if you're not entirely sure how to fix it, any input to point me in some direction would be helpful.
For reference, we're running Big-IP 11.5.1 HF8.
Thanks for reading.