Current status (6/9/2016) – Our engineers are working on the root cause of this unexpected behavior. In the meantime, please utilize the listed workaround and thank you for your patience. 

Quickbooks Online users are reporting that they are unable to edit account types for accounts that are not connected via Banking. […]

Resolution for 'connected via Banking issue: '“You can’t change the type of this account because it is reserved for the Online Banking feature,” error when editing account type of account not connected via Banking.' available: Yes.

The connected via Banking 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 connected via Banking issue yourself by looking for a resolution described in the article. If it is a complex connected via Banking issue or you are unable to solve the issue, you may contact us by clicking here or by using other connected via Banking support options.

For more information about resolving issues related to connected via Banking in Quickbooks/QBO or to get support for the issue '“You can’t change the type of this account because it is reserved for the Online Banking feature,” error when editing account type of account not connected via Banking.', click the link below: