Hi @Creol1
I did not reproduce this issue at current time.
As you say, I turn off add-in acquisition first, then I deploy an add-in.
After the add-in is deployed, I open Office store, go to 'Admin Managed' and click 'Refresh', the new deployed add-in will show up.
- I suggest you determine if Centralized Deployment of add-ins works for your organization first according to the linked article.
- After the deployment is completed, please click "Open App' and choose Excel desktop client to have a check.
- You may sign out the organization account and close Office apps. Start Office apps and sign back your account for a test.
Besides, this issue is also related to Microsoft 365 Admin, which is not supported on Q&A forum. To help you better, it's recommended to post a new thread on Microsoft Tech Community. Or you may contact Microsoft for support directly.
If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.