Hi Zachary F,
So sorry for this inconvenience caused to you.
To narrow down the issue, it’s recommended to create a new Excel file with drop down lists.
If the issue doesn’t happen to the new file, it means this issue may be due to your current Excel file. It may be corrupted. Given this situation, you may try to restore the file to previous version.
For your information: Restore a previous version of a file stored in OneDrive - Office Support (microsoft.com)
If the issue also happens to the new file, it means your Excel app may be corrupted. And you may try the following suggestions.
Method 1: Please try to remove cache folder like below:
- Close Excel and then open Finder.
- Press Command + Shift + G, input “~/Library/Containers”, remove cache folder com.Microsoft. Excel folder to desktop.
(Please note: if you are using Big Sur, the cache folder named Microsoft Excel.)
- Open Word, and check if it works correctly.
Method 2: Please launch a safe mode/boot on Mac OS, to check if issue caused by cache or directory issue with startup disk.
If you need further help, feel free to contact me.
And for a better understanding of your situation, may I confirm the following information?
- The build and version information of your Mac? (Apple menu > About this Mac)
- The build and version information of your Excel? (Excel>About Microsoft Excel)
Best Regards,
May