GS724Tv4 SNTP time doesnot work

I got the latest firmware.

I set configuring System -> Management -> Time -> SNTP Server Configuration 

I used the Netgear SNTP time-f.netgear.com which was mentioned in https://kb.netgear.com/21835/How-do-I-set-the-named-Simple-Network-Time-Protocol-SNTP-server-using-the-web-interface-on-my-managed-switch 
The KPN SNTP time.kpn.net
And the ntp.pool.org SNTP 0.nl.pool.ntp.org for the Neterlands listed https://www.ntppool.org/zone/nl 

When configuring System -> Management -> Time -> Time Configuration -> SNTP

After applying it jumps back to Local. And the local clock is slower then the sntp clock. I set it at the correct time and 12 hours later it's 4 minutes off.

I also read other topics like this https://community.netgear.com/t5/Plus-and-Smart-Switches-Forum/Time-Configuration-problems-on-a-GS724Tv4/td-p/1180829/page/2

It is possible to ping and trace the configured SNTP 

I don't get SNTP to work on the GS724Tv4