I configure my modelmapper like so

@PostConstruct
    private void initMapper() {
        PropertyMap<TalTicketEntity, TicketDto> talTicketToTicketPropertyMap = new PropertyMap<TalTicketEntity, TicketDto>() {
            @Override
            protected void configure() {
                map(source.getSymphonyId()).setId(null);
                map().setDetails(new TicketDetailsDto());
                map(source.getThirdPartyId()).getDetails().getExternalTicket().setExternalId(null);
                map(source.getRequester()).getDetails().setRequester(null);
                map(source.getAssignedTo()).setAssignedTo(null);
                map(source.getDescription()).getDetails().setDescription(null);
                map(source.getSubject()).setSubject(null);
                map(source.getCommentEntities()).getDetails().setNotes(null);
                map(source.getAttachmentEntities()).getDetails().setAttachments(null);
                map(source.getLastModified()).setLastUpdatedDate(null);
                map(source.getThirdPartyTicketLink()).getDetails().getExternalTicket().setLink(null);
                map(source.getExtraParameterEntities()).getDetails().getExternalTicket().setExtraProperties(null);
                map(source.getStatus()).setStatus(null);
                map(source.getPriority()).setPriority(null);
                map(source.getTriggerName()).setTriggerName(null);
            }
        };
        modelMapper.getConfiguration().setMatchingStrategy(MatchingStrategies.STRICT);

        modelMapper.addMappings(talTicketToTicketPropertyMap);

    }

Then try to use it

TicketDto convertTalTicketToSymphonyTicket(TalTicketEntity talTicket) {
        TicketDto symphonyTicket = modelMapper.map(talTicket, TicketDto.class);

        TicketDetailsDto ticketDetailsDto = symphonyTicket.getDetails();
        if (ticketDetailsDto == null) {

but the details field is always null. which also means all the fields under it are not mapped/coppied over. FYI all fields on base TalTicket/TicketDto are coppied over.
What am I doing wrong here?