QB Issue Resolution:

You may be able to get it to import using the recommendations here:

BRC – QuickBooks 2019 IIF Import Changes and Recommendations

Resolution for Issue 'I contacted support early October about not being able to import .iif files. Support said it was a known error and engineers were working on it. When will this be fixed?' available: Yes (Solved).
Source: Intuit Community forum.

I contacted support early October about not being able to import .iif files. Support said it was a known error and engineers were working on it. When will this be fixed?: this 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 issue yourself by looking for a resolution described below. If it is a complex issue or you are unable to solve the issue, you may contact us by clicking here or by using other support options.

Support for BRC
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Error Recovery for BRC [Canada]
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