Keyboard and trackpad not working as normal

Please don't point users to this website as the CleanMyMac app is notorious for causing problems with macOS. These forums are filled with threads where users fixed their Macs just by uninstalling their CMM app.

For a 2015 MBPro when both the Keyboard & Trackpad stop working at the same time it usually indicates the Trackpad Flex Cable has failed and needs to be replaced. If the cable does not fix the issue, then it is possible the Trackpad has failed, followed by the Logic Board. Whenever the Trackpad fails or is not connected to the Logic Board it will also prevent the built-in Keyboard from working. This Trackpad flex cable has a high rate of failure on the 2015 MBPro.

Take a look at this article and see if it might be of some help.

https://macpaw.com/how-to/keyboard-trackpad-not-working