Welcome. Sometimes closing and reopening TC can work, so I would try that first. but if that doesn't work.
It sounds like you may need to re-load the configuration,
NOTE - doing anything typed below, will reset TC, so you will lose any customisation done since you last used 'Save-in', or if you have not previously used 'saved-in', it will reset TC for factory defaults.
Tools menu - Customise (or Tools menu - workspace - customise). In the options section of the dialog box,. Did you previously use 'Save in' to save your config. If yes, you can find the config you use from the drop-down box under the 'load from' button, and then click 'load from'. this will reset any recent changes to the workspace.
If not previously saved. Then under the 'load from' button, find one that you normally use, and click 'Load from', or simply click the 'Default' button. This will reset all the config to a TC default, or for that selected config. Check if your keyboard shortcuts now work.
If the above does not work. you may need to go on to deleting the built-in folder.
I cannot guarantee the above will work, but it does in some cases from my experience.