I had a chance to run this by our Retail team, who hasn't seen any other reports of the recent update affecting how your cash drawer operates. They did mention that if you see the "no sale button" as greyed out, then that means your printer is not connected. If the till is plugged into the printer, then this would explain why the till is not opening as the printer controls the opening of the drawer.
The Bluetooth may have been interrupted, which can cause this to happen. Typically restarting the iPad, and/or resetting the connections should resolve the issue. If not, please let me know as I can verify your account and take a closer look.
The POS works once at start of the day then 'No sale' button greys out for rest of the day.
Does this happen after a specific amount of transactions? Is there a regular pattern of when the button greys out?
If you're using the mPop, would you mind trying these steps?
The Cash drawer requires a connection to the receipt printer in order to operate. If the cash drawer is not "popping" open when a cash sale is made, then check the receipt printer connection. The cord that comes with the cash drawer to connect to the printer may look the same but have labels on either end of the cord-marked printer and cash drawer. It is crucial that these are plugged into the correct device.
Thank you for confirming. What we'll need to do from here is verify your account and review the issue further with our Retail team. For this, I have sent an email to the email listed on your Forums account with the subject "Shopify Forums Support." If you can reply there with the requested information then we can continue with the troubleshooting.
In addition, we will also need the logs for your device.