mdc does not showed up anymore when using logback.getMDCPropertyMap()

[bomanarakasura-unipin]

Hello, I was using old Otel Instrumentation v2.2.0-alpha and otel v1.36.0 and springboot starter

Previously, I was creating my custom Log message using following code :

@Override
    protected Map toJsonMap(ILoggingEvent event) {

        final Map<String, Object> map = new LinkedHashMap<String, Object>();

        addTimestamp(TIMESTAMP_ATTR_NAME, this.includeTimestamp, event.getTimeStamp(), map);
        add(LEVEL_ATTR_NAME, this.includeLevel, String.valueOf(event.getLevel()), map);
        add(THREAD_ATTR_NAME, this.includeThreadName, event.getThreadName(), map);
        addMap(MDC_ATTR_NAME, this.includeMDC, event.getMDCPropertyMap(), map);

Above code prints mdc to console like this :

{
  "timestamp" : "2025-10-13 13:47:23+0700",
  "level" : "INFO",
  "thread" : "http-nio-8083-exec-1",
  "mdc" : {
    "traceId" : "888bde93c8985d18ff07f1a981c6b8e1",
    "spanId" : "f9de7067761f5a80"
  },

But after I updated the version to Otel Instrumentation 2.20.1 and Otel 1.54.1, mdc map does not showed up anymore.
Any suggestions?

[laurit]

If you want someone to take a look then provide a minimal application that illustrates your issue along with any necessary instructions.