That has happened when I've tried it but then worked when retried.
Summary of route:- Brackla Way, Church Acre heading toward Coity, to 2nd r'about backtrack to Coychurch, Pencoed, Heol y Cyw common, Sarn, Cefn Cribbwr, Kenfig Hill, Margam, Water St, Kenfig, Porthcawl seafront, A48, Ewenny Rd, Ogmore, St Bride's, Marcross, Llantwit major, around RAF St Athan, left off B4265 to LLancadle, join A48 to Cowdridge down Primrose Hill