Steps to reproduce:

1. Create discovery rule with setting like in the pictures
2. Create auto registration rule like in the pictures.
3. Check frontend monitoring>discovery (no host is monitored)
4. Check postgresql server log less /var/lib/pgsql/11/data/log/postgresql-Wed.log

PostgreSQL error log:
2020-03-04 17:28:54.794 CET [15083] ERROR: null value in column "description" violates not-null constraint
2020-03-04 17:28:54.794 CET [15083] DETAIL: Failing row contains (10405, null, 78.156.156.27, 0, 0, , 0, 0, 0, -1, 2, , , 0, 0, 0, 0, null, 0, 0, 0, 0, 0, , , 0, 0, 0, , 78.156.156.27, 0, null, null, 1, 1, , , , , , 1).
2020-03-04 17:28:54.794 CET [15083] STATEMENT: insert into hosts (hostid,proxy_hostid,host,name) values (10405,null,'78.156.156.27','78.156.156.27');

Centos 7,
zabbix 4.4.1, 4.4.4, 5.0.0alfa2
DB 9.6,11

Expected:
Host is added and registered.