Finding the cause of your issue(s)
To find the cause of the issue(s) please do the following:
1. Update The Theme/Plugins
Ensure you using the latest version of the theme and required plugins. We will not look at any issues if you haven’t updated these. To update the theme and required plugins please refer to the theme documentation.
2. Switch Themes
If updating the theme/plugins didn't fix the issue go to Appearance > Themes and activate the Twenty Twenty-One theme and see if the issue(s) still occur. If your site has visitors you can use the Theme Test Drive plugin so your users don’t see the theme you’ve switched to.
If the issue(s) still occur this means the theme is not causing the issue and this is probably a general WordPress or plugin issue.
3. Deactivate All Plugins
To see if it is a plugin issue deactivate all activated plugins (except the plugins that are needed to test the issues). If this fixes the issue(s) this means the theme is not the cause. Reactivate the plugins one by one or in groups so you can identify which plugins are responsible.
4. If the theme is responsible
If the issue only occurs when this theme is activated it looks like the theme is responsible. Please provide WordPress admin access and I'll take a closer look.