Token drop down in custom email builder seems...screwy

My Mautic version is: 2.15.1
My PHP version is: 7.2.17

My problem is: Something appears to be amiss with my tokens. When creating a custom email to a contact, the tokens drop down isn’t populated with any of the fields related to the contact. No first name, no address, no phone number…nothing! The token drop down is populated with some options, but just nothing pertaining to the contact itself. Within the email builder, when I type an opening brace, ‘{’, none of the tokens that appear are the ones I would be expecting (but at least they match the drop down in the email builder!). The tokens are still functioning, as I can include {contactfield=firstname} in the email builder and I get the appropriate text in the email when I send it, but something with the drop down is screwy.

To FURTHER add to the mystery, when I’m creating a new email template in “code mode,” the key combination Ctrl + Space Bar brings up the long list of available tokens. However, when creating a custom email for a contact, the Ctrl + Space bar key combination doesn’t bring up the full token list. Maybe that’s the intended functionality for the custom email builder’s “code mode”, but I thought it seemed a little strange.

These errors are showing in the log: None

Steps I have tried to fix the problem: I’ve tried using different browsers, but so far that’s all I’ve tried. I thought that perhaps I had missed a configuration step when installing Mautic that’s preventing the tokens from working properly, but I can’t find anything in the Mautic documentation that discusses such configuration steps.