Are you doing your due diligence when applying for jobs and considering the right opportunities?  My experience has been that some employers will build up a job into something far greater than it is or, are otherwise not forthcoming about the reality of the job or the workplace.  I've been caught a couple of times, usually when I needed to get something quickly, not being careful.  Once realized, I didn't stay too long; on one occasion it was a single day.  I follow the saying:  "ride your gains and cut your losses"