You shouldn’t have to use Tobii Game Hub for MSFS.
Click on the Windows Search Bar, type in Control Panel and click on it. Click on Programs and Features and uninstall any other tracking software and related plugins. Click X to close off Programs and Features.
Click on the Windows Search Bar, type in Add or remove programs and click on it (this will list other apps not listed in Programs and Features). Uninstall any other tracking software and related plugins. Click X to close off Add or remove programs.
Click on the Windows Search Bar, type in Device Manager and click on it. Go through each category carefully looking for any devices(Eye Tracker 5 and EyeChip belong to Tobii) might be related to other tracking software and related plugins and uninstall them by right clicking on them and clicking on Uninstall device. Click X to close off Device Manager. Then reboot.
If that doesn’t fix it, don’t use Revo but rather contact Tobii support to obtain the official Tobii removal software and do a clean uninstall using their removal software and then reinstall Tobii software. Follow this guide step by step starting at step 35 and finishing at step 77 in this post: https://forums.flightsimulator.com/t/settings-setup-guide-for-the-tobii-eye-tracker-5/502973/10