[isf-wifidog] Login issues

[Peter]

We are running Wifidog but we regularly see issues. Let me describe 2 
that happened within the last week.

1) User with Turkish language locale. No automatic portal displayed. I 
manually entered the login IP and it appears. I logged him in, and it 
says he's logged in ok. BUT he cannot get to any other pages (Internet)

2) Another user today, but English settings. Australian user, clock set 
to Australian time zone (not our TZ), but clock is correct based on his 
time zone. Same behaviour as #1...

Any ideas? How to debug such situations?