Amazfit Watch faces

hello,

i have opened a topic for a problem of a watchface without hands here viewtopic.php?f=6&t=681

romstemp has resolved it. i didn't understand what have caused the problem.

today i have exactly the same problem, but i really want to understand what causes all these issues.
i use an old watchface i have made here https://amazfitwatchfaces.com/bip/view/23400
the 5cc2f14b02152_26042019.bin file works perfectly, i use it to just add the seconds hand.
i generate the preview image and the preview is exactly what i expect to have.

but when i upload it on my watch, there is no hands at all. it is sec_sans_pulse_packed-3427-40af3bb80a.bin

it is very very frustrating. maybe someone could resolve it as the last time but i want to understand what causes the problem, i just used the 5cc2f14b02152_26042019.bin file that works fine and pressed the "toggle" button in the wf editor to add the seconds hand.
so what is wrong? why the preview image is good and why it is not good when i upload it.

is it because i'm using firefox? the webeditor displays a message about an incompatibility problem.
but in this case why the 5cc2f14b02152_26042019.bin file works perfectly (it is also done with firefox).

Click to add a dot, right click to remove, drag to move. Max 24 dots for all arrows if you use 2 arrows and 30 dots if you use 3 arrows