Samsung J1253 Long spinning time. Normal?

My J1253 takes a long time to spin. It has done this from new.An engineer came from comet and said it's normal.
This is a Samsung J1253 washing machine & is just over a year old.It does not seem to matter about the size of load. When it comes to the spin cycle of any programme the timer showes 10 or 11 min remaining but the drum turns backward & forwards with the pump running for probably 10 min as if it is trying to ballance the load. It then starts the normal spin & count down. This turns the 35min quick wash into something like 1hr 15 min & can add upto 40min to longer programmes.The engineer said it senses an off balance load by looking at the motor current. Is it to senestive? Is this adjustable? Is this spin cycle time normal?
The pump & outlet pipe have been cheched for blockages.