Unity Playworks Plugin size breakdown tab final build size is under 5MB but in Unity Playworks its shows as being above 5MB
This is a known issue. There are some discrepancies between how estimates are done in Unity vs the final assets in an html5 playable. This is more likely to happen if there are a lot of image files in a project.
Possible solution:
Download the latest plugin version from your Unity Playworks account by clicking on your account name and going to ‘downloads’.
If the estimate and final sizes are still incorrect, try to putting your images into a single atlas file instead of individual files. This will help with overall size optimisation and load times as well.