Wrong output header in the archive report

[mattmary]

see https://wordpress.org/support/topic/diagnostics-archive-reports-outputs-as-application-json/

[rrk22k]

Tre

[rrk22k]

Y

[diosmosis]

I cannot reproduce this locally on the latest Matomo for Wordpress release. Given the lack of updates on the original issue, I'm closing this. If anyone is still experiencing this please leave a comment.