I understand that you have an HP Officejet 4620 e-All-in-One Printer that shows 'now copying page' on the display, but then the printer freezes up a and does not copy, even though it prints fine. I would like to help with that.
The first thing I would do is perform a Power Reset on the printer.
It may also help to make sure the printer's firmware is up to date. The current firmware version is CWM1FN1451AR. You can check the printer's firmware by printing a printer status report.
1. From the Control panel, select Setup, select Print Reports, then select Printer Status Report.
2. The Printer Status Report will be printed.
3. The current firmware revision will appear on the printed Printer Status Report.
If you are using the printer on a wireless network you can check for the update from the front panel by pressing the ePrint button, then select Settings. In the Settings menu select Printer Update, and then Check for Update Now.
Please let me know if this resolves the issue, or if you require further assistance.
In fact, if this helps you to reach a solution, please click the "Accept as Solution", and the "thumbs up" buttons down below in this message.:)
Please click “Accept as Solution ” if you feel my post solved your issue, it will help others find the solution.