I'm using Chrome, with only uBlock Origin Lite but disabling it ~shows no change~ appears to allow it to work.
Looking at the requests with uBOL disabled, app.68194690.js and 5.5caaec0f.js both returned 404, everything else returned 200/202.
and with uBOL enabled https://plausible.hey.si/js/script.hash.outbound-links.js shows as blocked. maybe that's the issue?