Unable to update firmware

Hi,

I saw other posts say having difficulties with firmware update, but I've not found a solution for my case.

It's the first time I do the update. My phone is an Honor 8 with Android 7.0.

I tried with firmware version 2V05 and 2V06.

I used nRF Toolbox as suggested.

Each upload attempt lasts between 1% to 5% (really rare), then encauters an error saying: INVALID OBJECT.

If I try immediately after, the error message becomes OPERATION NOT PERMITTED.

Fortunately, the Toolbox keeps the last uploaded point so I managed, in almost 1 hour, to reach 100%.
I tried every possible combination:
switching on/off the bangle, the app, the phone bluetooth...
with/without Wi-Fi, with/without location...
Nothing changes :(

At the end, once upload completed with a confirmation message I restarted the bangle but it is not booting correctly, It says:

sw reset
dfu zyos

booting...
btn1 = reboot

and nothing happens anymore.

Please, can you help me?

Thank you very much