Find is not finding character string

Hi

I have a cell that has approx 22000 characters. I'm trying to remove a specific character string from a cell by doing a find and replace with "". It works for characters in the first part of the cell but not for characters in the last part of the cell.

Example: I do a find/replace for the characters 21242 to "" in column A and I get the expected results. I do a find/replace on 69294 to "", again I get the expected results, but if I do a find/replace on 85203 to "", I get "Excel cannot find what I am searching for" (but its there!)

My cell size is within the max size of 32,767 characters so not sure why its not working.

Attached a sample worksheet.

Ideas? What other option do I have?