They know there is a problem.
I also had the 5% added as US$ without exchange rate to £ calculation. Myself and my TA have been assured that whilst I see it as added to my US$ obc, at their end they see two amounts, one in US$ and one in £ sterling.
I am not going to touch the £ and will await its exchange to $ in those few days prior to boarding as per usual. That’s when any unused obc in any other currency other than US$ is exchanged into $ for use on board. Its never a good exchange rate but does the job,