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I was able to replicate your problem on my system (Win 10, QGIS
3.10.5).<br>
<br>
I tried "Join attributes by location (summary)". This computed the
result in about 5 seconds. <br>
There are some anomalies in the data, however. For example, there's
an entry for Belgium with province value "Unknown" and no lat/lon,
so it doesn't get included in the total. Also, the point for
Northern Territories, Australia, lies in the ocean, so it is not
contained in the Australia polygon. <br>
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