CDS Freezing

Anyone having connectivity issues with the IP version customer display app on iOS? CDS freezes in middle of taking a customer's order. Merchant isn't aware until another customer advises them that their order isn't accurate. Merchant has to force close the CDS app and reopen it for it to reconnect and reflect the correct customer's order. This occurs at all locations using IP CDS version and has occurred several times during a shift. I confirmed that the IP address are reserved. Bluetooth worked pretty good as long as the iPads remained on and didn't enter sleep mode or turn off. Reconnecting Bluetooth always required more steps and even force closing both applications for it to reconnect but don't recall ever losing connection during use.