How to delete a speed dial in Asterisk/FreePBX

Using FreePBX 15. This is a test system for evaluating the possible use of FreePBX in our university environment. From a phone, I used the Asterisk star code *75 to enter a speed dial. Now I want to delete that. I cannot find any way to do it. Asterisk doesn't provide a cancellation code. I checked the Asterisk Phonebook, and my entry is not there, yet it is still active when I dial the speed code from a phone. Any help with this would be much appreciated. Thanks,