Batch characteristic in classification not updating

Hello expert,

I have created classification for batch (class type 023) with characteristic MCH1 -LWEDT to record last GR date. Batch number has to be entered manually during GR posting. And i expect that during GR posting, characteristic value of GR date will be automatically updated in the classification but i've found that it is blank.

My query is, do GR date in characteristic value of batch class can be automatically updated during GR posting?

If it yes, what's wrong with my class? and how to make it works as expected?

Really appreciate your help.

Thank you in advance