I just went through a similar issue. For some reason part of the layer that was going outside of the artboard area into the bleed area did not show on the exported pdf. I had to create new document, copy / paste all layers and then export worked as expected. Cheers, e.
Hi, in the last hour Affinity Designer started crashing. first time it crashed while working but last time it crashed I was in the Chrome browser window. Attached is crash info from OS. BTW ... great app. I enjoy using it. AD - crash info - 06012016.rtf