possibly late frosts with a combination of drying winds.
it is a common problem I am afraid.

can the pot be placed somewhere more sheltered?

Thanks very much for your reply. It is in a sheltered spot now but I will look to see if I can place it somewhere else and see if that works.

Is it getting enough water and, given that it is in a pot, have you given it a feed at all?

Hi Alan. Welcome to Goy. I have the same problem with my potted Acers as I live in a windy spot. Another member said that an Acer expert (RHS exhibitor) friend of hers said that Acers shouldn't have sun before 2pm. I think that's good advice too. Late cold spells are my main problem with mine. Trying to keep them out of wind and morning sun is a challenge!