If you're on a multi-monitor setup, you could try setting this in options:
If you're not using 2+ screens, here's some other things to try.
1. Run Excel through Safe Mode - Check the appearance of the Find menu in Safe Mode. Close/Re-open Excel in normal mode to check again. Sometimes running the app through Safe Mode irons out these quirks.
Open Office apps in safe mode on a Windows PC - Microsoft Support
2. Toggle the Windows the resolution. Switch the resolution away from the current resolution, let it take effect, then switch it back.
Hopefully, one of these solutions works.