update requests

Hi. I've set automation on a worksheet to send an update request on completion of a form - users all have the same permissions and the access is set to unrestricted. There are a couple of issues:

1) not everyone is receiving the update requests

2) for some who DO receive the update request and respond, their response is not being captured in the worksheet - but the pending update request disappears.

Hope that makes sense.

Can anyone help, please?