The thickness of the bow carried by the skeleton is twice as normal on 32x texture pack resolution, 4 times on 64x, and 8 times thicker on 128x texture pack.
See the attached image. I have resized the original vanilla (both skeleton and bow) to 32x, 64x and 128x.
I'm testing with the latest 1.16.0.63.
MCPE-65376 was supposed to have fixed this issue, but it is still here.
Thank you for the useful information and screenshot. I added it to the original report, MCPE-64417