The keystrokes M-<up>, M-<down>, M-RET etc. do not work as described in the manual in an ordered list, but they change all the plain list into an unordered list. What could have happened?
- Emacs v26.3
- Org mode version 9.1.9 release_9.1.9-65-g5e4542
- iMac 2015 OS X El Capitan
C-h c M-<up>say? Similarly for the others.-qoption (which will avoid loading your init file) and see if it still the case.