Composite + Colour + Thread will render error

[Adonis-Song]

MLT Version : 7.13.0 System Version: MacOS 11.5.1

Issue: The second frame and the third frame rendered error.

XML file

<?xml version="1.0" encoding="UTF-8"?>
<mlt LC_NUMERIC="zh_CN.UTF-8" root="/usr/bpmlt/bin">
	<consumer crf="21" f="mp4" frame_rate_den="1" frame_rate_num="22" height="720" mlt_service="avformat" movflags="+faststart" preset="veryfast" real_time="-3" rescale="bilinear" target="/Users/apple/Downloads/7569.mp4" vcodec="libx264" width="1280"/>
	<producer id="producer_video">
		<property name="mlt_service">avformat</property>
		<property name="resource">/Users/apple/Downloads/anastasiaop.mp4</property>
	</producer>
	<producer id="producer_black">
		<property name="mlt_image_format">yuv422</property>
		<property name="mlt_service">color</property>
		<property name="resource">#000000</property>
		<property name="length">167</property>
	</producer>
	<producer id="producer_color">
		<property name="mlt_image_format">yuv422</property>
		<property name="mlt_service">color</property>
		<property name="resource">#FFFFFF</property>
		<property name="length">167</property>
	</producer>
	
	<playlist id="playlist_video_0">
		<entry in="0" out="11" producer="producer_black"/>
	</playlist>
	<playlist id="playlist_video_1">
		<entry in="0" out="11" producer="producer_video"/>
	</playlist>

	<tractor id="Tractor_0">
		<track hide="audio" producer="playlist_video_0"/>
		<track hide="audio" producer="playlist_video_1"/>
		<transition>
			<property name="distort">1</property>
			<property name="geometry">0/0:640x360</property>
			<property name="mlt_service">composite</property>
			<property name="a_track">0</property>
			<property name="b_track">1</property>
		</transition>
	</tractor>

</mlt>

I dont know why, I try to disable composite_yuv function and just return a_frame, it rendered failed too.

It will be ok, If change mlt_image_format to rgba or yuv420p in colour or remove real_time.