Cell Value is | Not equal to
=""

my 2nd offering:
Formula is
=LEN($J$6)

my 1st offering:
Formula is
=LEN(INDIRECT(ADDRESS(ROW(),COLUMN())))

Try running the code below by itself in a fresh spreadsheet and look
at the conditional  formatting in J6 and play with the values in H6 and
I6. They all work (we are on the same page).
Note also what cgDQ contains.