Lightroom Classic freezes when bulk exporting images

Is it just LrC freezing, and the rest of the computer runs properly? Or does the entire computer freeze and you have to re-start the computer?

What version NUMBER of LrC? What version NUMBER of Windows?

In a first step try to reset the preferences of Lightroom Classic:  How to reset Lightroom Classic preferences (adobe.com)

It's recommended to backup your preferences before you reset the preferences to the default settings: 

https://helpx.adobe.com/lightroom-classic/kb/preference-file-and-other-file-locations.html

Do you get an error message? If yes, please post the message word-by-word.

Is your system up-to-date? Do you have installed all recent updates and patches for the operating system and the device drivers, especially the graphic driver. If you have a NVidia graphic card installed, make sure that you are using the recent Studio version of the driver, not the Game Ready version.

Please provide a copy of your 'System Info'. This can be get from the LrC Help > System Info menu item. There's a copy button in the System Info dialog. Press this button and paste the info into your next forum post.