Are you using items in your bills (instead of expenses)?  If you enter a bill, your balance will go up until the bill is paid.  The payment reduces the a/p balance.

Resolution for 'balance go up issue: 'When I create a bill why does the balance go up?' available: Yes.

The balance go up issue or error code is a known issue in Quickbooks Online (QBO) and/or Quickbooks. Support for this issue is available either by self-service or paid support options. Experts are available to resolve your Quickbooks issue to ensure minimal downtime and continue running your business. First try to resolve the balance go up issue yourself by looking for a resolution described in the article. If it is a complex balance go up issue or you are unable to solve the issue, you may contact us by clicking here or by using other balance go up support options.

For more information about resolving issues related to balance go up in Quickbooks/QBO or to get support for the issue 'When I create a bill why does the balance go up?', click the link below: