The applicant has a job but his job is not fixed. The bank is worried that he can't repay the loan, so he will slow down, or the applicant has an overdue record, which will affect his credit.
The applicant has a job, but his job is not fixed, or his occupation belongs to wholesale, self-employed, direct selling, logistics, entertainment and catering, security and other freelance jobs. Because of the unstable income, the bank is worried that he does not have enough repayment ability, so he is unwilling to issue them a credit card.