Hi Marcus, I have had the OS fault light show up twice now on my +6 and like you can’t pinpoint any style of driving to be the cause.
Mine is also at the dealers - be interesting to compare.
There also appears to be little advice on what do do if the fault light illuminates.....
Mike

Mike
1982 4/4
1999 +4
2004 Roadster S1
2010 Roadster S2
2021 Plus 6