_paq.push() was used but Piwik tracker was not initialized before the piwik.js file was loaded. Make sure to configure the tracker via _paq.push before loading piwik.js. Alternatively, you can create a tracker via Piwik.addTracker() manually and then use _paq.push but it may not fully work as tracker methods may not be executed in the correct order. ["setCustomUrl", "https://www.mbatious.com/recent"]
So I've added GA to the mix. I did that with adding it in the same custom header as to validate that my Piwik installation is not on the fritz. Comparing the two I see a little fewer unique visits between the two in piwik but almost exactly the same amount of pageviews.
Nodebb is still off by a factor of three in unique visits and around a factor of three to ten in pageviews.
I tried you repo, but unfortunately the Mongo container fails:
mongodb_1 | Error relocating /usr/bin/mongod: _ZNK5boost16re_detail_10600031cpp_regex_traits_implementationIcE17transform_primaryEPKcS4_: symbol not found
mongodb_1 | Error relocating /usr/bin/mongod: _ZNK5boost16re_detail_10600031cpp_regex_traits_implementationIcE9transformEPKcS4_: symbol not found
nodebbdockerdev_mongodb_1 exited with code 127
Searching StackOverflow it seems this is an issue with Mongo on Alpine...
(I using Docker beta for MacOS, but I don't think this is the issue)