Recently my C4 Cactus 1.6 automatic has developed a intermittent but annoying fault. When in drive leaving a tight parking space and just wanting it to roll slowly forward with no power, it jerks like you are stamping on the brake. Noticed it more when A/C is on, and usually only when moving off after being parked. You would be forgiven for thinking the brakes were sticking, but they're not.
Car had a full service and the Citroen technician noticed it as well, but download showed nothing. It feels like it isn't producing enough power to roll like it should. Never a issue on a hill though. Occasionally it will roll back on a hill as well, but not sure if this is linked.
Very intermittent, but very annoying.
Faults and Technical chat for the Citroen C4 Cactus