@Dharmaraj - I see what you are saying (and I added an additional screenshot to your post).

The Miro for Mapping & Diagramming help center article states that the UML (and other shapes) pack is available for the Education Plan, so I am not understanding why these templates are being blocked for Education Plan users (my spouse has an Education Plan and they are blocked for her too).

The Templates section of the same help center article does not mention this limitation either.

I will open a support ticket from this post and will report back with what the support team has to say.

Thanks for the quick reply @Robert Johnson! 

I created one earlier this week and was unable to add a new one today.

Looking forward to getting a solution. Thanks again!

For now, if there is one that you want, let me know and I will create it and share a board like with you in view-only mode. From there you can open the board, click on the board title, and use the Duplicate button.

Actually, here are all seven :)

https://miro.com/app/board/uXjVPqtRmKE=/

Thanks for the board :)
It seems I can still access some shapes from diagramming section but not the templates. 
But I can continue with the provided board and the ones I had already for sure :D
 

You’re welcome! Hopefully this was all just an oversight.

Update #1 from Miro support:

Thank you for reaching out to the Miro Support team to report this.
 
I understand that the user is trying to access the UML templates under their Education plan. I tested myself and also could not open them as they are locked. I have reached out to our team in charge of templates to verify if any changes were made to the access. As you stated, our Help Center article shows that the UML templates would be available to users on an Education plan. 
 
I will be sure to reach back with more updates.

Update #2 from Miro support:

Education plans should have access to Smart Diagramming such as UML. Our team has identified the cause of this issue and is working diligently to fix it as soon as possible. We are currently prioritizing this issue and are taking all necessary steps to correct it.
 
We will continue to update you as soon as we have more information. Please do not hesitate to reach out, if you have any questions or concerns.
 
Thank you for your patience and understanding.

Update #3 from Miro support [ISSUE RESOLVED]:

My team informed me that there has been a fix released. I tested on my end, and I have access to the UML templates. Please check that it is also working for you.

@Dharmaraj - I have tested this on my spouse’s Education Plan and she can now use the UML templates again. The issue appears to have been resolved.

Thanks a lot for all the help @Robert Johnson!
Yes, I can now use the UML diagrams as well.