Thanks for using Bitnami. I'm sorry but I don't fully understand the issue you are running into.
Could you please let us know how you created the page in WordPress? Could you please share a screenshot of the issue?
could you please let us know the directory you are trying to modify with Filezilla?
We have a Support Tool that will gather relevant information for us to check the servers' logs and the permissions of the different folders. Could you please download and 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 outputted by the tool in your reply.