I would like to grep for the exact match of "er", but grep -w finds a partial match in words with non-Latin letters such as "ß" in addition to the exact match. The command below finds "er" in "großer", and "weißer". The expected behavior is that grep only finds the exact match of "er" in the string below with no partial matches.
echo "großer, Teller, der, er, weißer" | grep -w "er"
I also tried exporting LC_ALL=C, but this did not solve the problem.