This is still happening for us. We are using metabox to manage thousands of devices and changes happen all the time. It seems to happen when there is more than one form open for the same object. Sometimes we need to update one field for multiple devices and doing it one at a time is the only way.
My gut tells me it has something to do with the revision copy being generated each time a post is edited. Almost like it is trying to save multiple revisions with the same post id.
Anyway, if there is a fix for this please let me know.
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