Stay on "Connecting for file list (async)" forever

Hi, in the last few days I have a problem with one linux host. The log keep staying at “Connecting for file list (async)”.
this is the output of “urbackupclientctl status”
{
“capability_bits”: 69697,
“finished_processes”: [{
“process_id”: 2,
“success”: true
}
,{
“process_id”: 3,
“success”: true
}
,{
“process_id”: 4,
“success”: true
}
,{
“process_id”: 5,
“success”: true
}
,{
“process_id”: 6,
“success”: true
}
,{
“process_id”: 7,
“success”: true
}
,{
“process_id”: 8,
“success”: true
}
,{
“process_id”: 9,
“success”: true
}
,{
“process_id”: 10,
“success”: true
}
,{
“process_id”: 11,
“success”: true
}
,{
“process_id”: 12,
“success”: true
}
,{
“process_id”: 13,
“success”: true
}
],
“internet_connected”: true,
“internet_status”: “connected”,
“last_backup_time”: 1607595087,
“running_processes”: [{
“action”: “INCR”,
“eta_ms”: 0,
“percent_done”: -1,
“process_id”: 16,
“server_status_id”: 78,
“speed_bpms”: 0
}
],
“servers”: [{
“internet_connection”: true,
“name”: “xx.xx.xx.xx”
}
],
“time_since_last_lan_connection”: 11835646824
}
and this is the log from the server

15/12/20 00:17 INFO Starting scheduled incremental file backup…
15/12/20 00:17 DEBUG : Doing backup with hashes…
15/12/20 00:17 DEBUG : Doing backup with intra file diffs…
15/12/20 00:17 DEBUG : Connecting for filelist…
15/12/20 00:17 DEBUG : Waiting for filelist
15/12/20 00:17 DEBUG : Connecting for filelist (async)…

what I have to do?
Thanks