App update doesn't activate on client side javascript changes

I’ve just had to reinstall Windows on my computer and in the process reinstall Meteor (the most current version).

I copied across all of the client/server/package files from an archived version of my project and it’s mostly running fine except the project only auto updates when I make changes to html or css files (and it does so very quickly!) When I edit the javascript files it not only doesn’t auto update but it ignores my changes even when I manually refresh the page. I have to stop the project and then start it again to see those changes. Also worth noting that server side javascript changes activate an update immediately, this is exclusively on the client side.

Any thoughts? I don’t even know where to begin with debugging this