The VBE keeps an internal cache of variable names, including the casing, so even though you found a variable called cell
, and renamed it to be something else, VBA still thinks it is a valid name, and so it is preserving the casing across all usages of that text.
You can trick the VBE into resetting the variable casing (and this also works for casing problems on methods too) by temporarily declaring a variable with the correct casing:
Public Cell as String
And then deleting that variable. You should then find that all of the casings are fixed throughout your project (and any project that refers to it).