Event R401 not executing

Dear Experts,

During billing i am posting some debits and credits at the same time to customer account. I want them to be cleared when i invoice them. i read posts of other people who have similar problems but after debugging i realised that system is not executing event r401 at all for some reasons.

i have made the config where we need to define clearing type and clearing category and check the acct maint indicator. table te514 and te529 also configured

Also please tell if there is any way of knowing which clearing variant is being executed at acct maint(if any)

Any help would be highly appreciated

Thanks!