"RFC5424 is not a valid syslog facility string" unable to configure RFC5424 syslog format in logback and sprinboot - spring-boot

Question

I have configured syslog appender in my logback.xml
When I run my spring-boot application, I get the error "RFC5424 is not a valid syslog facility string"
below is my logback.xml
<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="true">
<property name="DEV_HOME" value="logs"></property>
<!--console appender-->
<appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
<encoder>
<pattern>[%d{yyyy-MM-dd HH:mm:ss}] - %msg%n</pattern>
</encoder>
</appender>
<!--all logs-->
<appender name="FILE" class="ch.qos.logback.core.FileAppender">
<file>${DEV_HOME}/debug.log</file>
<encoder>
<pattern>%date %level [%thread] %logger{10} [%file:%line] %msg%n</pattern>
</encoder>
</appender>
<!--only controller class logs-->
<appender name="SPECIFIC_CLASS" class="ch.qos.logback.core.rolling.RollingFileAppender">
<file>${DEV_HOME}/sizeTimeOutputlogFile.log</file>
<encoder class="ch.qos.logback.classic.encoder.PatternLayoutEncoder">
<pattern>[%d{yyyy-MM-dd HH:mm:ss}] %p %c{1.} [%t]- %m%n</pattern>
</encoder>
<rollingPolicy class="ch.qos.logback.core.rolling.TimeBasedRollingPolicy">
<fileNamePattern>${DEV_HOME}/archived/sizeTimeOutputlogFile.%d{yyyy-MM-dd}.%i.log</fileNamePattern>
<timeBasedFileNamingAndTriggeringPolicy class="ch.qos.logback.core.rolling.SizeAndTimeBasedFNATP">
<!--Max Size of file to start Archive -->
<maxFileSize>10KB</maxFileSize>
</timeBasedFileNamingAndTriggeringPolicy>
<!-- Days till log history to keep -->
<maxHistory>3</maxHistory>
</rollingPolicy>
</appender>
<!--syslog appender-->
<appender name="SYSLOG" class="ch.qos.logback.classic.net.SyslogAppender">
<syslogHost>127.0.0.1</syslogHost>
<facility>LOCAL0</facility>
<port>514</port>
<throwableExcluded>true</throwableExcluded>
<suffixPattern>%syslogStart{RFC5424}%n</suffixPattern>
</appender>
<!-- Setup the root category, add the appenders and set the default level -->
<root level="ERROR">
<appender-ref ref="FILE"/>
<appender-ref ref="STDOUT"/>
</root>
<!-- Specify the level specific to controller -->
<logger name="sysLogger" level="DEBUG" additivity="false">
<appender-ref ref="SYSLOG" />
</logger>
<logger name="com.syslogspringboot.syslog.poc" level="ERROR" additivity="false">
<appender-ref ref="STDOUT" />
<appender-ref ref="SPECIFIC_CLASS" />
</logger>
with a different suffix pattern it works fine.
Can someone help