Welcome to the forums,
Though we had just fixed
Bug 24884 - zmtlsctl doesn't update zimbra.web.xml.in or zimbraAdmin.web.xml.in .4/.5 & the all time favorite
Bug 5594 - TLS mode "both" causes redirection limit problem in .5 I sort of remember another bug but can't find it - could you update to 5.0.6 & try again?
5.0.6 is out!