UniFi UPS Tower: static IP bug, weird power/load readings, and LB only after sitting at 0%?

I've had a UniFi UPS Tower for less than a week and I'm trying to figure out whether what I'm seeing is normal behaviour, firmware weirdness, or if I just got a bad unit.

Firmware is 1.6.1.

First issue was setting a static IP.

The UPS is connected untagged to my Servers VLAN:

• VLAN 70
• 10.70.0.0/24
• gateway 10.70.0.1
• DHCP range 10.70.0.50-199

On DHCP the UPS got 10.70.0.90 and worked normally.

When I switched the UPS network setting from DHCP to Static, without manually changing anything yet, it copied the IP and subnet correctly but populated:

Gateway: 10.10.0.1 DNS: 10.10.0.1 

10.10.0.1 is the UCG-Fiber address on my Management VLAN, not the gateway for the Servers VLAN.

The correct gateway is 10.70.0.1.

The first few times I tried changing the UPS to a static 10.70.0.9 I completely lost access to it and eventually had to factory reset it.

After noticing the wrong gateway, I first tested Static while keeping 10.70.0.90, manually set the gateway to 10.70.0.1, then moved it to 10.70.0.9. After an Ethernet disconnect/reconnect it finally stabilized and has remained accessible in UniFi and via NUT.

So that one looks very much like a bug in how the Static form is being populated.

The second weird thing is the load/power reporting.

On mains I was seeing around:

Load: 12% Real power: 72 W 

The moment I removed mains and it switched to battery:

Load: 21-31% Real power: 126-186 W 

Nothing was added to the UPS at that moment.

I also have a separate metered socket on the UPS input. Adding a real load, for example a fan, clearly increases power at the wall, but the UPS's own load/power values while on mains barely seem to react.

Another thing I noticed from the logs: realpower seems to just be calculated directly from load.

The UPS is rated at 600 W and the values line up exactly:

So realpower doesn't appear to be an independent measurement at all.

Maybe this has something to do with it being line-interactive and the UPS having a different measurement path while the inverter is active, but right now I don't really trust either Load or Real Power as actual metering.

The third issue is the one that worries me more.

I did a controlled discharge test while logging NUT every 2 seconds.

UniFi was configured with:

Start safe shutdown when battery runtime remaining reaches: 5 min 

The important points from the test were:

+00:00 AC removed, UPS goes OB +20:34 runtime reaches 300s, battery 26% +24:49 runtime reaches 0s, battery 2% +24:51 battery reaches 0% +32:19 LB finally appears 

So when estimated runtime reached the configured 5 minutes, NUT still just reported:

OB DISCHRG 

No LB.

It then reached:

battery.runtime: 0 battery.charge: 0 

and stayed like that for roughly 7.5 more minutes before LB finally appeared.

When LB finally appeared, the UPS LED started flashing red and my NUT clients immediately started their normal shutdown sequence.

For transparency, somewhere around 5%-0% I manually shut down my NAS because I was getting nervous that LB might never arrive, so this wasn't a perfectly constant-load battery test. The Proxmox hosts stayed running until LB though.

The UPS still had enough battery to keep supplying output after the machines shut down.

I've also separately tested NUT shutdown using upsmon -c fsd, and that part works perfectly: secondaries shut down immediately and the primary shuts down last after its VMs/LXCs.

At this point I'm thinking about eventually using my NUT primary to trigger FSD itself when:

status = OB AND runtime <= 300s 

instead of trusting the UPS's LB flag, while leaving LB as a final emergency fallback.

Has anyone else with a UPS Tower seen the same things?

Especially:

• Static IP picking the Management VLAN gateway instead of the actual network gateway
• realpower apparently just being load % × 600 W
• Load/Real Power being basically useless on mains and jumping massively when switching to battery
• Battery/runtime reaching 0 and sitting there for several minutes before NUT finally reports LB
• The UniFi "5 min safe shutdown" setting apparently not corresponding to the NUT LB threshold

I'm mainly trying to establish whether this is just how the UPS Tower currently behaves, whether 1.6.1 has some reporting bugs, or whether I should be considering an RMA because my particular unit is behaving badly.