Hi @Elaine_Lin, we are also running into this issue!
It seems to impact Non-null origin iframes in particular.
Some additional context & reports for things that sound similar/related across the community forum (all of which have gone unanswered):
We would love to get this resolved / any suggestions for workarounds!
Also want to echo that it is very difficult for plugin authors to catch issues like this before a plugin is released, because you cannot test a plugin in the browser before it is released! So any discrepancies between the Figma desktop app and the Figma browser experience go undetected through the review process . Any possibility of being able to test dev plugins in the browser in the future?
Lastly, is there a way via the plugin API or otherwise to detect whether a plugin is being executed in the browser or desktop app? Then we can at least ship a quick patch release to notify users about the missing drag-and-drop behavior on the web.