DicomImportService stops listening on the port

[ghost]

When sending a batch of images (around 4000), the DicomImportService suddenly stops listening on the port (after say ~1k images). Thankfully this is logged in the ctp.log

09:19:07 WARN  [AbstractImportService] ----------------------------------------------------------------
09:19:07 WARN  [AbstractImportService] DicomImportService
09:19:07 WARN  [AbstractImportService] Duplicate UID in last 10 objects: null
09:19:07 WARN  [DicomStorageSCP] DicomImportService accepted 1.2.40.0.13.1.299070121314638859894107211504735236376 from 127.0.0.1(AidenceAET:CustomerAET)
09:19:07 WARN  [DicomStorageSCP] DicomImportService: request parameters:
09:19:07 WARN  [DicomStorageSCP]     AffectedSOPClassUID:    1.2.840.10008.5.1.4.1.1.2
09:19:07 WARN  [DicomStorageSCP]     AffectedSOPInstanceUID: 1.2.40.0.13.1.299070121314638859894107211504735236376
09:19:07 WARN  [DicomStorageSCP]     TransferSyntaxUID:      1.2.840.10008.1.2
09:19:07 INFO  [ServerImpl] Stop Server listening at port 11112

We had logging of the DicomImportService enabled:

<DicomImportService
            logConnections="yes"
            logDuplicates="yes"
            [more attributes] />

Disabling the logging in the config resolves this isssue and the port will not be closed.
Don't know why the server hangs up when logging is enabled though ...