The rewrite rules need one slug to indicate the taxonomy. The default for tags is
tag. You can change it at Settings > Permalinks > Tag base. But it still should be one slug for all tags or WP won’t know how to handle each different one.
If you have to have different ones (why? when each tag is already different?), you could use a Redirect plugin.
Thanks for reply! I’ve already fixed it with plugin for permalinks. Thanks!