One Docker container stopped resolving DNS properly

I have weird problem with my Mailcow instance. One container (Postfix) has started resolving DNS partially. The problem is only with this particular container which I don't understand. It is causing that emails are not being sent from it due to domain name not found error.

root@6c751ea397ad:/# host wp.pl
Host wp.pl not found: 2(SERVFAIL)
root@6c751ea397ad:/# host mx.wp.pl
Host mx.wp.pl not found: 2(SERVFAIL)

root@6c751ea397ad:/# cat /etc/resolv.conf 
search domain.com
nameserver 127.0.0.11
options ndots:0

but with external DNS:

root@6c751ea397ad:/# host wp.pl 1.1.1.1
Using domain server:
Name: 1.1.1.1
Address: 1.1.1.1#53
Aliases: 

wp.pl has address 212.77.98.9
wp.pl mail is handled by 0 mx.wp.pl.
wp.pl mail is handled by 5 mx5.wp.pl.

for different domain:

root@6c751ea397ad:/# host -t any o2.pl             
o2.pl has address 212.77.98.29
o2.pl descriptive text "facebook-domain-verification=0omejgqroqocgh4efgrbu8bovlazni"
o2.pl descriptive text "v=spf1 include:wp.pl -all"
o2.pl mail is handled by 10 mx.tlen.pl.
o2.pl has SOA record ns1.go2.pl. root.go2.pl. 2020111002 3600 1080 1209600 7200
o2.pl name server ns1.go2.pl.
o2.pl name server ns2.go2.pl.
root@6c751ea397ad:/# host -t any mx.tlen.pl
mx.tlen.pl has address 193.222.135.150

This one is really weird:

root@6c751ea397ad:/# host -t any company.mail.protection.outlook.com 
Host company.mail.protection.outlook.com not found: 2(SERVFAIL)
root@6c751ea397ad:/# host -t any outlook.com 
outlook.com has SOA record bn7mgt0101dc013.prdmgt01.prod.exchangelabs.com. msnhst.microsoft.com. 2014796278 300 900 2419200 60
outlook.com has address 40.97.148.226
outlook.com has address 40.97.153.146
outlook.com has address 40.97.161.50
...

Each other container works fine:

root@c228923398e8:/# host wp.pl
wp.pl has address 212.77.98.9
wp.pl mail is handled by 5 mx5.wp.pl.
wp.pl mail is handled by 0 mx.wp.pl.
root@c228923398e8:/# host mx.wp.pl
mx.wp.pl has address 212.77.101.4
root@c228923398e8:/# cat /etc/resolv.conf 
search domain.com
nameserver 127.0.0.11
options ndots:0

I've tried so far:

• removing and reinstalling resolvconf from the host
• Adding 1.1.1.1/8.8.8.8 to /etc/resolvconf/resolv.conf.d/base and /etc/resolvconf/resolv.conf.d/head
• Adding DNS to: /etc/docker/daemon.json
• Adding static DNS to mailcow docker-compose
• Disabling firewall

all without any luck.