You can’t shut it off directly.  As long as you stay on this release you’ll have this new requirement to use a password with your file’s current contents:

It’s been stated by Intuit that the trigger for the password is a variety of PII data in your file (including SSN’s, company […]

Resolution for 'Constant issue: 'Constant login required' available: Yes.

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

For more information about resolving issues related to Constant in Quickbooks/QBO or to get support for the issue 'Constant login required', click the link below: