What is the problem with reverse DNS lookups?

Question

Domain Name System

If you resolve by name, then the address is the one you need,
but if you try to do the opposite, then the address is displayed wrong.
For example

nslookup video.onko4.local показывает верный адрес 192.168.1.3
nslookup 192.168.1.3 показывает gateway.onko4.local

with other records the same trouble.
reverse zones

1.168.192.in-addr.arpa. 10800 IN SOA onko4.local. root.onko4.local. 2007012001 (
                                                10h  ; slave-server connection period
                                                1h   ; retry
                                                1w   ; life-time
                                                1h ) ; negative ttl

                NS root.onko4.local.

1 PTR onko4.local.
2 PTR www.onko4.local.
3 PTR gateway.onko4.local.
4 PTR sip.onko4.local.
5 PTR nx.onko4.local.
6 PTR video.onko4.local.
7 PTR db.onko4.local.
8 PTR files.onko4.local.
9 PTR xms.onko4.local.

Direct zone

$TTL	3600

@	IN	SOA	ns.onko4.local.	root.ns.onko4.local.	(
  2007012000;	Serial
            10h ; slave-server connection preiod
                                                1h  ; retry
                                                1w  ; lifetime
                                                1h ); negative ttl

  IN	NS	ns.onko4.local.
  IN	NS	ns2.onko4.local.

localhost		IN	A	127.0.0.1

ns			IN	A	192.168.1.5
ns2			IN	A	192.168.1.5

@			IN	A	192.168.1.8

www		IN  	CNAME	@
req			IN  	CNAME	@

gateway          	IN	A	192.168.1.5
sip                 	IN	A	192.168.1.4
nx                   	IN	A	10.214.2.131
video		IN	A	192.168.1.3
db			IN	A	192.168.1.199
files			IN	A	10.214.2.135
xms			IN	A	192.168.1.7

I don't know why, the gaps are gone..

Answer 1

So what's the problem then? You have it written:
fix gateway.onko4.local. at video.onko4.local.