The most obvious symptom of the problem is that the AutoTimer entry is missing from the main menu.
If you press MENU from live TV and the menu does not show an AutoTimer entry:
- Use USB to flash 17.5-20180417
- Do not restore settings from backup
- Proceed with the installation wizard
- Apply any online updates that may be offered
- Configure settings as desired
- Backup your settings
Once you have completed these steps, the main menu should have an AutoTimer entry.