Questionable if this is a bug, but as far as the user can see, the achievement is complete given the granularity is at the level of 1000s of complete items. Of course, the achievement was completed seconds later. I recall something similar recently for research was altered to only report complete whole percentages. In this case, perhaps only show complete whole 1000s?
[0.17.52] Achievement appears complete but isn't
Re: [0.17.52] Achievement appears complete but isn't
Thanks for the report however I don't consider this worth tinkering with. The GUI is general-purposed logic which doesn't pay attention to the actual number range it's showing. Limiting it to 1000s might make this one nicer but there's nothing that prevents a 300,000,000 counter from not working nicely.
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