FixHub unexpected charging behavior?

Hi, two days ago I received my new portable soldering kit.
Unfortunately I was not able to get it to work right out of the box.
The FixHub was completely dead/discharged.

I was able to get it at least turning on the display after charging it for a few (20ish) minutes with one of my USB-C PD Chargers.

Since it did still not boot up as described in the manual I wanted to give updating the software a try.
So I connected it to my laptop and updated it from 1.4.2 to the current 1.5.0 software revision.
While doing so, I noticed that the charge percentage displayed in the console was only 3%.

After that I reconnected my charger and was expecting to see a steady draw of around 40W or so, but instead the consumption was changing erratically within a second from 1W to 39W to 10W to 16W back to 1W and so on.

As it is stated that the it is using a li ion battery I expected that it is using an CC-CV method (constant current, constant voltage).

To rule out any compatibility issues I tried to charge it with other PD power supplies (and cables) I had available. But no combination did bring any stable draw from the FixHub.

I did leave it charging in one configuration until it reported 100% charge (which took over 6h!).

When it reported full capacity I tried again to connect for charging and now it was drawing a stable 10W.

I then wanted to solder a bit with it, but was faced with another problem. I got it connected and wanted to start soldering, but then the FixHub powered down and I was unable to start it again with the blue button...
I called it a night and wanted to take a look in the web console, but somehow after connecting to the laptop the FixHub came back to live and was now again responding to commands via the button.

So the next day I could finally do some soldering, which it was doing well and it was fun using the station (also not consuming much charge for around 15 minutes of use).

Afterwards I wanted to check if the charge behavior now was different (maybe just some sort of "breaking-in/activation" protocol after deep discharges?).

So I discharged the hub by charging some other devices (smartphone, smartwatch) to around 60%.

Then again when plugging in one of my pd chargers the same behavior as initial. Multiple changes in power draw within the second...

So is this the "normal" behavior expected from the device, or do I have a defective one?

TL;DR

FixHub did come deep discharged, charging it with several different pd power supplies was taking over 6h showing power draw changing wildly within seconds.

Here are some pictures of the chargers I tested as well as videos of the problem: