Rendering issues when switching/animating image source

Description

What MCU/Processor/Board and compiler are you using?

TTGO T-Watch 2020 / LVGL v7.0

What do you experience?

I created a small mario bros animation where the character jumps at regular interval. See the following video.

As you can see in the video, from time to time, the image gets dirty and white pixels are rendered around the character.
Any idea why this is happening?

What do you expect?

No random white noise around the images.

Code to reproduce

The code for rendering mario can be found here: https://github.com/wizche/ttgo-smb/blob/75df0a7e8fb3011f1353eb3817e7397935f53be9/src/mario.cpp#L14

Screenshot and/or video

Can your reproduce it

  1. with a very minimalistic code? (only a background + Mario images).
  2. in a simulator?