There are 2 possible reasons for this:
- The Filter: By default, the cashflow view defaults to the current month+year. It's likely that you have been entering income/expense for a different month/year. If so, please do make sure you change your filter to reflect the period you are updating - you should see your income/expense entries there.
2. A Pending Form Submission: You may have a pending form to be paid which locks the period. Once you cancel a pending form (or complete the payment process) you may proceed with adding income/expense for the affected period. To find out how to cancel a pending form, you can see the instructions here.