If you change your job during the Earning Arrestment, then your Wage Arrestment will stop, due to having no earnings for that employer to deduct your wages from. It is your duty to ensure that you inform the Sheriff Officers of your change in employment.
However, your previous employer can be instructed to supply details of your new employment to the sheriff officers where it is known. Most-likely because you had to give them as an employment reference.
The Earning Arrestment, therefore, will most likely follow you.