Ah ha.. that’s the trick!
Thanks a lot!
I tried many times, in fact I found that if I click on the ‘Open image in new tab’, it does show the logo image that uploaded and assigned by me.
However, the page’s header’s logo is not updated, this really strange. What else I can try here?
OK, i found that the problem only if I had put this text box inside an existing column. If it is put as individual element on the ‘form template’, then it is OK.