In my application spring boot webflux application I have an upload use case which requires the upload of 1 and more empty files. The upload endpoint is pretty simple in itself and goes like this:

public Mono<ResponseEntity<ResponseDTO>> upload(@RequestPart("files") Flux<FilePart> fileParts) {
    // fileParts.flatMap(filePart -> will only contain the last empty file always if more than one empty file is uploaded)
}

The problem is that if more than 1 empty files are uploaded, then only the last one is considered.

This issue started when upgrading from spring boot 2.7.18 to 3.3.5.

I saw a similar issue to this #30953 which has already been closed but I'm still having something similar. I tried though to reproduce it using the webTestClient in an automated test but to no avail. Maybe this explains #30953.