Reddit is implementing changes to its API reporting. In short:
“Currently if a community has chosen to not allow free form reports from users, our API did not enforce that setting,” the developer team posted on Reddit. “We’re here to give you a heads up that will be changing on Monday, September 21st, 2020.”
Starting on September 21st, Reddit will migrate to a “strict validation” policy for reports. If a custom report is sent from a subreddit that has not allowed free form reports, the API will return a 400 Bad Request error. Free_form_reports will be set to false in subreddit settings. All report reasons must match or an error message will return.
Currently, the current free_form_reports can be set to disallow custom reports from subreddits, but the setting never restricted third party clients from sending custom reports. To prepare for the change, users can test the upcoming behavior by adding strict_freeform_reports=1 to a POST to report. This will return a 400 if the report is sent and not allowed. Reddit recommends that those using UI reporting begin checking to see if free form reports are currently enabled. To learn more, check out the API docs and the changelogs.