Check Materialisation runs status
Once the Persistence Engine is activated, it'll run at the specified schedule period. In order to validate that the Persistence are going fine and troubleshoot any issues you could have, you can check the Persistence runs status in the Workbench.
In the Workbench, once the Persistence Engine is activated, you'll have a new item that appears on the left panel, click on it to see past Persistence Runs and trigger a new one:
By clicking on the + icon, you'll be able to start a Persistence Runs directly.