Help with running backend .jsw files

Edit: So after some debugging, it looks like the exceljs module is borked. If I remove the exceljs imports the rest of the module works fine. Except now I have to reimplement all the logic with another excel library. Maybe xlsxwriter.
I’m at a loss as to why this is happening. Is it because I’m not a premium user? But that doesn’t make sense, because exceljs was working fine last week.
Did I cross some magical trial period after which npm modules don’t work anymore?