Thanks for using Bitnami. Could you please tell us how are you trying to upload those files to your server? We have a guide regarding SFTP that may be of help in that case
Also, could you please try to upload any file to different location outside of the
/opt/bitnami directory? You can try
/home/bitnami for example. Do you get the same issue with that new location?
Apart from the above, we have a Support Tool that will gather relevant information for us to analyze your configuration and logs. 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.