Short update,
This is the content of hnasa.log for a user not working:
2018-10-17 12:34:54 *** running with new mail receiving and parsing ***

And this is the content of the same file for a working user:
2018-10-17 12:35:45 *** running with new mail receiving and parsing ***
2018-10-17 12:35:45 *** Using Clock Replacement ***
2018-10-17 12:35:45 *** using a freelist to keep track of free space ***
2018-10-17 12:35:45 *** RELOAD UI FULLY ***
2018-10-17 12:35:45 *** RELOAD LANGUAGES ***
2018-10-17 12:35:46 Database ID is: 75D6B599BB02E2AD0FCBD5379B36ED5C
2018-10-17 12:35:46 mrp->sz: 1488 stat: 0 ec: -1 em:
2018-10-17 12:35:46 mrp->sz: 11874 stat: 0 ec: -1 em:
2018-10-17 12:35:46 mrp->sz: 422 stat: 0 ec: -1 em:
2018-10-17 12:35:46 8.4 2018-07-26 (build 84192011)
2018-10-17 12:35:50 SendWebRequest    54.228.222.177    447    /HTSLogAction.hal    SendLogActionReply    res = false

2018-10-17 12:35:50 Steng database