zmproxyconfgen | NullPointerException

[simred]

Hi,
I've a fresh ZCS 8.8.9 OSS multi node setup on Oracle Linux 7 x86_64.
On proxy node if I execute the following command I got a NullPointerException

[zimbra@ml-fe ~]$ /opt/zimbra/libexec/zmproxyconfgen -D
[] INFO: Strict server name enforcement enabled? false
NGINX Keyword: core.cprefix
Description: Common config file prefix
Value Type: STRING
Controlling Attribute: (none)
Default Value: nginx.conf
Current Value: nginx.conf
Config Text: nginx.conf

NGINX Keyword: core.includes
Description: Include directory (relative to ${core.workdir}/conf)
Value Type: STRING
Controlling Attribute: (none)
Default Value: /opt/zimbra/conf/nginx/includes
Current Value: /opt/zimbra/conf/nginx/includes
Config Text: /opt/zimbra/conf/nginx/includes

NGINX Keyword: core.ipboth.enabled
Description: Both IPv4 and IPv6
Value Type: ENABLER
Controlling Attribute: (none)
Default Value: true
Current Value: false
Config Text: #

NGINX Keyword: core.ipv4only.enabled
Description: IPv4 Only
Value Type: ENABLER
Controlling Attribute: (none)
Default Value: false
Current Value: true
Config Text:

NGINX Keyword: core.ipv6only.enabled
Description: IPv6 Only
Value Type: ENABLER
Controlling Attribute: (none)
Default Value: false
Current Value: false
Config Text: #

NGINX Keyword: core.tprefix
Description: Common template file prefix
Value Type: STRING
Controlling Attribute: (none)
Default Value: nginx.conf
Current Value: nginx.conf
Config Text: nginx.conf

NGINX Keyword: core.workdir
Description: Working Directory for NGINX worker processes
Value Type: STRING
Controlling Attribute: (none)
Default Value: /opt/zimbra
Current Value: /opt/zimbra
Config Text: /opt/zimbra

Exception in thread "main" java.lang.NullPointerException
at com.zimbra.cs.util.ProxyConfGen.displayVariables(ProxyConfGen.java:2714)
at com.zimbra.cs.util.ProxyConfGen.createConf(ProxyConfGen.java:3103)
at com.zimbra.cs.util.ProxyConfGen.main(ProxyConfGen.java:3280)

Any help will be greatly appreciated.


P.S.
[zimbra@ml-fe ~]$ zmprov gs `zmhostname` zimbraServiceEnabled
# name ml-fe.tecnocasa.internal
zimbraServiceEnabled: memcached
zimbraServiceEnabled: stats
zimbraServiceEnabled: proxy


Tnx & br