Plusnet 'High' Firewall Blocks NTP Sync

[#1]

As the subject suggests I recently increased the firewall to high setting on https://www.plus.net/member-centre/broadband/firewall and since then my router has not been able to sync with NTP.

I continually get these errors:

(138108.060000) NTP synchronization failure!

and the time/date are wrong.

Considering it's Plusnet's firewall that I am using you would have thought it would be able to communicate with it's own servers.

Any help would be appreciated - I don't want to lower the firewall setting.

[#2]

@Correlated 

For information, my firewall is set to high and I have no problems accessing the NTP server.

Have you tried a factory reset on your hub? keep the switch closed for at least 20 seconds or so.

[#3]

Just had my firmware updated and it seems to have resolved the issue

Software version 4.7.5.1.83.8.289.1.3 | Last updated 28/10/21