vendor Ref. no. and ref2 in account balance shows different value

Hi friends,

Please find the below images of vendor account balance, A/P invoice and change log on A/P Invoice.

For doc num 10928, in A/P invoice Vendor Ref No is showing 2319.. but in Account balances in Ref2 it is showing 2311.

There is change log details on A/P invoice.

Please tell me why it showing wrong ref no.