Sparkpost: ‘json_array’, needs to ‘json_object’

Hello!

When sending a test email through Sparkpost, I see the following error in the Sparkpost events dashboard:

field 'content.headers' is of type 'json_array', but needs to be of type 'json_object'

I also have Sendgrid connecting, and there everything works fine. Can it be that Sparkpost requires the data to be sent in a different format?

Thanks!