Simulator requests resulting in 400 error

[sreime]

Hello, @actions-on-google team,

lately, I´m having massive problems developing actions for google.
Unfortunately, the simulator only accepts the first input. Every other request is resulting in an error.
By checking the network tap I saw that the https://console.actions.google.com/m/actions/simulator/simulate request is resulting in a 400 error. The problems starting 2 or 3 Weeks ago.
Doing the same thing on my mobile phone with the assistant app works fine. Also no issue with the google home itself.

Kind regards
Sebastian