Hello Harry1945,
The ink in the MB2720 will not slide to the middle unless the printer detects that the ink is low or empty. If the ink level shows up with a question mark, it would mean something is wrong with the ink tank or the printer hardware. The printer will not be able to slide the ink to the middle on it's own since it can't detect the ink level. In this situation, you can unplug the printer and check the ink on the inside left to see if the tanks are not loaded properly or are leaking. If so, you can try sliding the ink to the middle by hand to see if you can push the ink back into place.
If that does not resolve the issue or if you are unable to slide the ink to the middle by hand, it looks like the printer needs service. You can check your available service options by logging into your MyCanon account. Some third party ink tanks can also cause ink level detection issues and cause the problem that you are describing.
