A late night case of "I wonder if" has got me up. Set the command and data times up higher, still the same.
Not real happy with a couple of the SMD solder pads for the pic. The leg has solder, and the pad has solder, but not convinced they are soldered together. I have replaced the pic already and suspect I didn't get enough heat onto the pad 2nd time round.

Tomorrow I'll resolder at the workshop and cross my fingers.