Subnet filtering bug: showing the same subnet several times

There's a bug in filtering subnets. I have only agent-kea configured. It reports there are 9 subnets. I went to DHCP->Subnets and used "6" as a filtering string hoping to see only 192.0.6.0 subnet. However, it now shows 11 subnets including 3 copies of 192.0.6.0.

If I use a longer filter string 0.6.0 it now limits the subnets correctly, but still shows 3 copies of 192.0.6.0 subnet.

This is what I have in the db:

stork=> select * from subnet;
 id |        created_at         |    prefix     | shared_network_id | client_class | addr_utilization | pd_utilization 
----+---------------------------+---------------+-------------------+--------------+------------------+----------------
  1 | 2020-04-20 11:35:49.21212 | 192.0.5.0/24  |                 1 | class-01-00  |                  |               
  2 | 2020-04-20 11:35:49.21212 | 192.0.6.0/24  |                 1 | class-01-01  |                  |               
  3 | 2020-04-20 11:35:49.21212 | 192.0.7.0/24  |                 1 | class-01-02  |                  |               
  4 | 2020-04-20 11:35:49.21212 | 192.0.8.0/24  |                 1 | class-01-03  |                  |               
  5 | 2020-04-20 11:35:49.21212 | 192.0.9.0/24  |                 1 | class-01-04  |                  |               
  6 | 2020-04-20 11:35:49.21212 | 192.1.15.0/24 |                 2 | class-02-00  |                  |               
  7 | 2020-04-20 11:35:49.21212 | 192.1.16.0/24 |                 2 | class-02-01  |                  |               
  8 | 2020-04-20 11:35:49.21212 | 192.1.17.0/24 |                 2 | class-02-02  |                  |               
  9 | 2020-04-20 11:35:49.21212 | 192.0.2.0/24  |                   | class-00-00  |                  |               
(9 rows)

and this is how it looks filtered: