This is the iframe snippet -- I redacted the URL to our Metabase instance and the string associated with the specific embedded dashboard.
<iframe title="metabase" src="https://urltometabase/embed/dashboard/verylongstring#bordered=true&titled=false" name="metabase-iframe" frameborder="0" data-testid="metabase-iframe" class="css-uwwqev ecmr43a6"></iframe>
For the server-side code snippet, I believe we use the default generated by Metabase. I have recordings of the bug and what the dashboard should look like, but I won't be able to share them because they were recorded in our production environment.
If visuals are definitely needed I can see if I can get permission to share a recording from our demo environment which has the same dashboard we're having problems with, but no actual customer data.