Cannot Post POS Closing Entry

We are not able to post POS Closing Entry:
After the POS Sales are done, we click on Close POS and in the POS Closing Entry, enter the amounts and click on Save,
We then get a message that ‘Submit this document to confirm’ and when we click on Submit we get a confirmation, we click on Yes, and then nothing happens.

It shows that the document is not saved and is in draft state, no Sales invoices were created and no inventory effected in stock ledger.

Our erpnext version is: ERPNext: v13.20.1 (version-13)

Kindly help

I have the same issue. However I do not even see a submit button in the first place. I have checked the permissions and they all seem ok.

We have faced this issue after upgrading from ERPNext 12 to 13.