You could try go to Tools/ Customize/ Options and reload your cfg(UI) and see if that helps.
Or close TC and go to windows Apps and Features and Select TC 2018, then click on Change and when you get the option to choose Repair, do that, this should copy in some basic shortcut funtions.
But many time, a simple close and restart TC will sort many issues, so maybe try that first if you dont have done so already.
V18, V19, V20, V21, 2015/ 16/ 17/ 18 Pro. Platinum
Deluxe V20, V21, 2015/ 16/ 17
Windows 10 Home Premium 64 bit, 32 GB
NVIDIA Geforce GTX 780m, 1 GB