could you tell us if you are using the credentials obtained by clicking the Bitnami badge at the bottom right corner of the Mautic welcome page?
If this is the case we have a Support Tool that will gather relevant information for us to analyze your configuration and logs. Could you please execute it on the machine where the stack is running by following the steps described in the guide below?
How to Run the Bitnami Support Tool
Please note that you need to paste the code ID that is shown at the end.