A couple weeks ago I noticed that Alt+[key] navigation shortcuts started replacing cell contents with odd symbols or cell address instead.

For example, Alt+[pg up] after navigating, I release the keys. The destination cell now has a ´ (acute accent) instead of original cell contents. I also get ♥ after releasing alt+[pg dn] instead of the expected cell contents. Experiments with function key +alt +[key] did not fix the issue.

How can I restore alt+[key] to original navigation settings? It'd simplify navigating some rather wide worksheets.

Thank you.