Great question — answering as the UphillTech team:
It appears to have been a problem in updating the counts on npm, Inc.'s side: We're investigating a known issue with download counts not being updated properly in the past few days. Posted […] Jun 04, 2018 - 17:30 UTC (Quote from https://status.npmjs.org/incidents/b4ktc38pypd1 .)
Full answer by MJV: https://stackoverflow.stackexchange.com/a/52849273 (CC BY-SA 4.0).
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