Data too long for column item_name in Stock Entry

Hello,

I got data too long error and I changed data length to 500, but it still getting same error. After the change of data length, even strings with less than 140 length gives me same error.

I checked on column in the database it’s varchar(500) which is more than enough

What could be the problem here?

After traceback python code, the issue is on item_name column in Serial No doctype, not stock entry detail