I can type freely anywhere in that sheet. Do you only have the problem with this one worksheet?

I have had problems with other worksheets but it turned out those problems were caused by reference back to another worksheet. When I solved the reference problem it went away. This worksheet doesn't refer to any other worksheet.

With this worksheet try deleting some numbers and retype numbers back into those cells. Save the file, open it back up and again try typing in numbers. See if you can get the problem to surface after typing in numerous cells.

I have been entering numbers from the number pad. I just double-clicked in a cell. It showed the cursor so I decided to type the number using the keys along the top of the keyboard. I checked the number pad and my NumLock wasn't on. Sheesh!!! so many ways to stub a toe. Probably operator error, but I will post once more to inform whether or not this completely solved the problem.

Thank you for looking at this.