Our Live Chat agent has already sent you an email regarding this.
Anyways, I have tried to reproduce this issue from the localhost and was unable to reproduce this issue as everything seemed perfectly well.
Please make sure that you have updated to the latest versions of WP ERP (1.3.13) and WP ERP Attendance add-on (1.1.4).
If both of them are updated and you are still facing issue, please provide me a temporary admin credentials and FTP access through our Support ticket through this link so that I can look into this issue and fix it.: https://wperp.com/contact/