It appears you are logged into a different Group in the same Browser window.
You cannot log into multiple Teachme Biz Groups in a single Browser window.
Please take one of the following actions.
Log Out of the Group you are currently logged into, then Log into the Group you want to access
Related: Log into a Group again (Web Browser version)
https://teachme.jp/8/manuals/42394351
Open a separate Browser window and log in
Related: Log into a Group (Web Browser version)
https://teachme.jp/8/manuals/4929434