centos8 container: iptables works incorrectly

originally reported via openvz forum
https://forum.openvz.org/index.php?t=msg&th=13636&goto=53659&S=13bdeba1fd466825d7014c25f6f8d7d2#msg_53659

Kernel 3.10.0-1127.8.2.vz7.151.14
Virtuozzo Linux release 7.8.0 (627)

- created new template: yum install centos-8-x86_64-ez ; vzpkg create cache centos-8-x86_64
- created VE, started ve
- once inside VE:

systemctl disable firewalld ; systemctl stop firewalld
iptables-save | grep -c TEST
iptables -N TEST ; iptables -A TEST -j ACCEPT ; iptables-save | grep -c TEST



Result:
CT-105 /# iptables-save | grep -c TEST
1
CT-105 /# iptables -N TEST ; iptables -A TEST -j ACCEPT ; iptables-save | grep -c TEST
iptables: Chain already exists.
19
CT-105 /#