i can't change my background color in header "Background gradient" not working

First of all, try to do these steps as quickly as possible, so your visitors do not notice the process:

1. disable TagDiv Composer
2. uninstall TagDiv Composer
3. clear cache (if cache plugin exists)
4. install TagDiv Composer
5. activate TagDiv Composer
6. clear cache (if cahce plugin exists)

Also make sure your WordPress and plugins are up to date.
Sometimes, the issue can be from a plugin conflict, that’s why, please deactivate ALL plugins except tagDiv ones, also if you are using a cache plugin, deactivate it, clear all cache and try again.

Let us know about your results!

Thank you!