It appears that I can create a filter rule via a client and it gets saved successfully. When trying the same thing on the web interface, saving to an already created or new folder underneath the INBOX, it appears as if i cannot save. The filter applied on the client transfers to the web interface but not the other way around.
What do you mean by client? An IMAP client?
The filter creation on the web interface is not working correctly. This will be fixed in an upcoming build.
Yes I meant Imap client. Thank you for your reply.