request.field('test', 'str') throwing error Failed to execute 'append' on 'FormData': parameter 2 is not of type 'Blob'.

I am getting error from version 7.1.1. On older versions works fine.

Start at the request.field('test', 'str') entry point and reproduce the failure with version 7.1.1, comparing it with an older working version. Trace the FormData append call and identify the expected handling for string values. Done means the reported request no longer throws the Blob type error and the existing behavior remains covered by a regression test.

Written by the indexing model from the issue text.