`persistent_users` aren't updated

[krizhanovsky]

Config has

PERSISTENT_USERS_ALLOW=True
PERSISTENT_USERS_WINDOW_OFFSET_MIN=60
PERSISTENT_USERS_WINDOW_DURATION_MIN=60

and there are users

:) select distinct hex(tft), status, count() as count from access_log group by tft, status;

   ┌─hex(tft)─────────┬─status─┬─count─┐
1. │ C6610B269D970015 │    304 │     3 │
2. │ C6610B269D970015 │    200 │    43 │
3. │ 0D378F00A5F5001D │    200 │  1051 │
4. │ C6610B269D970015 │    206 │     2 │
5. │ 908BA2B344C30015 │    200 │    11 │
6. │ 66CB0DAC148C0010 │    200 │    18 │
7. │ 398A4371C0320015 │    304 │     1 │
8. │ 398A4371C0320015 │    200 │     6 │
9. │ 66CB8F0004E3001A │    200 │     6 │
   └──────────────────┴────────┴───────┘

However, persistent_users are never populated:

:) select * from persistent_users;

0 rows in set. Elapsed: 0.002 sec.