Captive Portal Logon Problems
it's a bit weird but some phones sometimes have trouble login on the captive portal page… after they've inputted the voucher code(s) it just brings them back to the portal page ,
but this rarely happens , around 1 out of 15 chance that our clients has this problem . happens mostly on IOS gadgets
some of them have been able to go login the portal before
That happens when the device thinks the page it was originally going to is the portal page itself.
I have found that about the only way to defeat it is to use an after-authentication URL redirect.
You could probably get clever and test if the redirect URL is the portal page and, if so, issue a redirect somewhere, else redirect to the original browser request page.
Or just forget about trying to send them to the page they originally requested and do the after-auth redirect.