Could you provide URL and temporary wp-admin access?
1/ We did not face the mentioned warning before. Have you tied to follow their suggestions (clear cache and disable all 3rd party plugins to check if one of additional plugins is a reason for the problem) ? Do you have warnings with our theme only or when Twenty Twenty-One theme is activated also? Try to contact the support of Loco Translate plugin.
2/ Activate a default theme and check then. Our theme should not be reason for this. Try to get more info from the test system you are using or your hosting provider.
3/ Provide FTP access also.
4/ Activate our White Label Branding plugin – https://xstore.helpscoutdocs.com/article/108-white-label-branding-plugin
One standard license is valid only for 1 project. Running multiple projects on a single license is a copyright violation.