Are you including the bleed in the PDF export?
Yes, I am ticking the use document bleed settings which is set to 2mm
What size does it show in Acrobat? You can see the size with Preferences>Page Display>Always show document page size.
When you export to PDF are you using any printers marks?
Printer marks will cause the PDF to be larger than 103x214mm.
In any case, you should get rid of the frame at the edge of the card.
They cannot accurately cut the cards to such exact tolerances.
This is the whole reason for bleeds in the first place
Each sheet goes through the press or printer slightly offset and the bleed and margins (safe area) are necessary to cut a stack of cardstock (or any other media).
Even if you move the frame inside the edge of the card, it will be very obvious because the frame cannot be exactly centered on each card.
You should however, make sure your textured background extends to fill the bleed area.