@Lucy Edwards - I just tried both the context menu and shortcut actions and they are working for me. I tried this from Chrome and the Miro desktop app on Windows 11, 64-bit. I tested on Text and a Flowchart object:

What is your setup? Have you tried disabling any browser extensions?

@Robert Johnson I think I see now what's happening by style it only mean the fill and the boarder? 

Not the actual size of the shape or the font style? (do you know any way how to do this? the problem I'm having is that when I create a process map, i make all the shapes smaller so then when I want to change a shape, I have to resize it every time - so I'm looking for a 'Set default style’ type function)

Thanks for your help! 

@Lucy Edwards - You’re correct!

However… maybe there is a bug (or a missed requirement) when it comes to diagram objects. For example, with Text and Shape objects, the following style elements are being copied-pasted:

1. Font type/
2. Font color
3. Font highlighting
4. Background fill
5. Border color

But with Diagram objects, the font type and font highlighting are not being pasted/updated on the target object.

I will report this to the support team to see if it is a bug. I will update this post with what the support team tells me!

@Robert Johnson amazing thank you :) 

Thank you for bringing this to our attention! 
We’re actively investigating the issue reported here and will get back to you with any updates :) 
Please bear with us!

Thank you from Miro support team.

Update from Miro support:

We recently retested and could not replicate the issue. Can you please confirm if the copy style feature is working as expected for you?

Confirmed: Font type and highlighting are now copying-pasting on diagram objects: