working in spreadsheet, can't delete

I downloaded version yesterday. When I try to make corrections to my cells formulas, or wording within the cell, I backspace over the item I want to delete, or I will highlight the what I want to delete, but after I’ve made my changes, the original is still there - sometimes with the new input added and sometimes ignoring the new input. This is true whether I am working from the cell directly or up in the edit bar making the changes. When I am in the edit bar and I highlight the part I want to delete, or write over, it gives me the NO symbol (circle with a line drawn through it).
I have searched through the menus to find a cause for this or a way to correct it and am unable to find it.
I believe this is a debug issue, but if I post to debugger they want me to do the debugging and I do not know even the tiniest about writing programs.
(I don’t recall for sure but I think I’m having the same problem in writer.) OS Microsoft Windows 10

Can you make a screenshot of it? Can you replicate the steps to reproduce the effect so others can reproduce it? If you can, then please file a bug, see ask LibreOffice for a little information and link to bug site