Thank you all!
Omar, I put same resolution in AE than PNG’s properties (I checked on windows properties) so even like that it didn’t work. The 50% resizing was about Blender resolution before rendering, to have a shorter (ahaha 9 hours) render time. Maybe I should have rendered at 100% with 2048 x 858 directly rather than doing 50% of 4096 x 1716.
Nevermind so I didn’t try rendering again because last one took 9 hours. I prefered try with Blender’s video sequencer and… the result is finally good!! I really don’t understand why AE resolution was bad this time whereas for the dice render it worked perfectly.. Adobe’s mysteries
https://jmp.sh/s/ExEczAvJO3mDS2WipUxw (video)
https://ibb.co/L1Wj18q (PNG)
https://ibb.co/FHHV8Vf ( frame video)
https://ibb.co/D9mnv81 (pixellised frame video)
Thanks a lot again !