Canvas draw line in LV_IMG_CF_1BIT mode , the line is not continue

Description

Using the canvas in LV_IMG_CF_1BIT mode, draw line is not conitue. if using LV_IMG_CF_TRUE_COLOR_ALPHA , draw line is continue and beatiful.

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

What LVGL version are you using?

V8.3.1

What do you want to achieve?

draw line line be continue and fast

What have you tried so far?

Code to reproduce

Add a code snippet which can run in the simulator. It should contain only the relevant code that compiles without errors when separated from your main code base.

The code block(s) should be formatted like:

    lv_obj_t *canvas = lv_canvas_create(scr_signature);
    lv_obj_set_size(canvas, CANVAS_WIDTH, CANVAS_HEIGHT);

    lv_canvas_set_buffer(canvas, cbuf, CANVAS_WIDTH, CANVAS_HEIGHT, LV_IMG_CF_ALPHA_1BIT);
    lv_canvas_fill_bg(canvas, lv_color_white(), LV_OPA_0);

Screenshot and/or video