Unable to connect to Orthanc with DicomUseTls=true

Our Dicom application is able to send to and receive from local and remote Orthanc databases with DicomUseTls=false in orthanc.json. But the association could not be set up when DicomUseTls is set to “true”. The following is the related settings in Orthanc.json for TLS. Certificates (orthanc.crt, dcmkt.crt) were created with OpenSSL (Version 3.2.1)
{

“DicomTlsEnabled” : true,
“DicomTlsCertificate” : “orthanc.crt”,
“DicomTlsPrivateKey” : “orthanc.key”,
“DicomTlsTrustedCertificates” : “dcmtk.crt”,
“DicomModalities” : {
“dmctk” : {
“Host” : “127.0.0.1”,
“Port” : 4242,
“AET” : “DCMTK”,
“UseDicomTls” : true
}
}

}

The last log message in Logs folder is:
“CommandDispatcher.cpp:284] Receiving Association failed: DUL network read timeout”
I hope you can help me out. I appreciate your reply and suggestions.