Memory leak when using lv_fs_if


I am trying to output an image via an external file.
If I output the image through C Arry, then 2 kB of RAM is used, if through FAT FS + lv_fs_if
(pre-converting to *.bin), then 21 kB of RAM is used. The image is 20x20 px.
Moreover, if you do lv_obj_del (img); memory is not freed!
Since I did everything on libraries, I decided to ask if anyone had such problems and what can you advise. Thank you

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

STM32F4, custom board

What LVGL version are you using?

LVGL - 8.0.1
lv_fs_if - latest version
FAT FS - from the composition latest version CubeMX

What do you want to achieve?

Output image from external file without memory loss

What have you tried so far?

I tried to read files through JPG and PNG decoders, the result is the same. FATFS checked by reading txt file through lv_fs_read. Everything is working.

Code to reproduce

    lv_obj_t * img1 = lv_img_create(parent);
    //consumes a lot of RAM
    lv_img_set_src(img1, "1:res/img.bin");
    //consumes little RAM
    lv_img_set_src(img1, &img_test);

If you open this way, the memory is also not freed.

    lv_fs_file_t f;
    lv_fs_res_t res;
    res = lv_fs_open(&f, "1:res/img.bin", LV_FS_MODE_RD);

Screenshot and/or video

If possible, add screenshots and/or videos about the current state.