Smart-UPS RT 6000 RM XL - NTP & DST broken

[chiller15]

I have a Smart-UPS RT 6000 RM XL that simply will not sync the time correctly when using NTP. If I configure the NTP settings, it picks up a completely different time...not just a different time zone (which are usually 1 hour apart), but it will report being behind something like 1 hour 24 minutes, which seems oddly specific. It will also drift further away if I leave it configured like this. If I disable the setting and re-enable it, I'll get a completely different random time. I have used various NTP servers, including our internal NTP server (which syncs from uk.pool.ntp.org and other internal services pull correctly from that), as well as other Internet based NTP servers, including directly to uk.pool.ntp.org, 0.uk.pool.ntp.org, 1.uk.pool.ntp.org, 2.uk.pool.ntp.org, 3.uk.pool.ntp.org, etc.

I have also tried a manual time and using DST and syncing from my local machine, but the time will also drift massively when using DST.

The only way I can stop the drift is to manually specify the time and disable DST, but I have to remember to manually change the time whenever DST changes.

Is this something that can be resolved? I'm using firmware revision 452.19.W.