Here are several ways to search for a string in one column in another. The last one worked the best for me, looking for column E in column C.
Just past in the first row of column D1 and copy down.
=NOT(ISNA(MATCH($K1,$G$1:$G$99504,0)))
=COUNTIF($K$1:$K$99504,$G1)>0
=COUNTIF($C1,”*” & $E1 & “*”)>0