Microsoft Idea
In GP2015, web client was based on Silverlight and had some issues such as only working on specific computers and specific web browsers. In GP2016, they redesigned web client on HTLM 5, which means it can now be used on different browser and on almost any device.

In the web client with GP 2015, a user could copy and paste the project and cost category during time entry.
With the new web client in GP 2016 and GP 2018, a user is no longer able to copy and paste. This is known as quality issue (# 76652). There currently is no other copy/paste workaround so the user will need to select/enter the correct project ID and cost category on the lines.
Category: Web Client
Ideas Administrator

Please review this documentation for the feature release