Hi Marie,
They are right in that there should be no air in the basket but it may be no big deal. Indicates there is not enough flow to purge the basket of air. From your comment 'there is enough pressure' are you referring to flow from the return jets or actual pressure and what is the gauge reading? Low pressure would indicate a suction side restriction while a high pressure indicates a pressure side restriction. I usually see a few small bubbles kicking around mine and I ignore them and they eventually disappear. I remember you have solar panels on your roof so have you tried bypassing them? Also what size pump did you replace?
Al