Why nslookup stops resolving after setting ns ?

Hello,
I am seeing strange behaviour on my Centos 7 VM and I can't find explanation. Can someone help me to understand, if there is something wrong with DNS setup?
When I run nslookup on one domain, it works fine always. But when I do -type=ns , it stops resolving exactly for 60 seconds and after that, it works fine.
Code:[root@centos73-01 ~]# date
Tue Aug 8 21:13:44 UTC 2023
[root@centos73-01 ~]# nslookup -type=ns mlp.geo.t-mobile.com
Server: 172.28.45.4
Address: 172.28.45.4#53

** server can't find mlp.geo.t-mobile.com: NXDOMAIN

[root@centos73-01 ~]# nslookup mlp.geo.t-mobile.com
Server: 172.28.45.4
Address: 172.28.45.4#53

** server can't find mlp.geo.t-mobile.com: NXDOMAIN

[root@centos73-01 ~]# date
Tue Aug 8 21:14:46 UTC 2023
[root@centos73-01 ~]# nslookup mlp.geo.t-mobile.com
Server: 172.28.45.4
Address: 172.28.45.4#53

Non-authoritative answer:
Name: mlp.geo.t-mobile.com
Address: 66.94.31.118

[root@centos73-01 ~]#Thanks