Steps to reproduce:
- Start editing in VE a page with a notice (e.g. https://en.wikipedia.org/w/index.php?title=This_page_does_not_exist_yet&veaction=edit&action=edit)
- Close the notice.
- Switch to NWE.
- Close the notice again.
- Switch to VE.
- Close the notice again.
Steps 4 and 6 should not be necessary, once you closed the notice it should be kept closed, even if you switch the mode.