Forum Discussion
Did you ever sort this one out? We switched from ADFS to the Big-IP for SSO and some of our Skype for Business users are seeing this same behavior.
I also tried disabling clustered multi-processing https://support.f5.com/csp/article/K14358 in order for the delay to be more effective. It's hard to say whether that helped or not, but I left that setting in place regardless.
The browser will end up doing 3 POST requests to the F5 during CHAP authentication. On the F5 side, the first two seem to execute just fine, the third one never comes if the defect is realized. From the browser's perspective, the 2nd POST doesn't get a reply from the F5. It's hard to troubleshoot because when I run it through Fiddler, it works just fine, possibly because of a change to the timing. This problem is also tricky to troubleshoot because the ECA module appears to be a black box on the F5 side that I can't see inside.