Glitch when trying to display few data entries sharing only two different dates

I have a scatter plot (grouped) that works correctly for every other dataset except for this one. Here, the last date should be in 2024, but is displayed in 2027.

This one only has 4 entries that should display on 2 different dates.

,id,country,affiliation,draft,title,submission_date,wg,docid
0,116736,,ARTICLE 19,draft-irtf-hrpc-research-14,Research into Human Rights Protocol Considerations,2017-10-01,,RFC8280
1,119890,,Oxford Internet Institute,draft-irtf-hrpc-research-14,Research into Human Rights Protocol Considerations,2017-10-01,,RFC8280
2,116736,,University of Amsterdam,draft-irtf-hrpc-guidelines-21,Guidelines for Human Rights Protocol and Architecture Considerations,2024-09-01,,RFC9620
3,125317,,GG,draft-irtf-hrpc-guidelines-21,Guidelines for Human Rights Protocol and Architecture Considerations,2024-09-01,,RFC9620

Now, if I change the month of the last entry, then the display works. If I add a 5th entry, the display also works. I'm not sure what to make of that:

Might that be a tiny bug?

Reproduce the grouped scatter plot using the four supplied rows, especially the two 2017 and two 2024 submission dates. Compare the rendered date with variants that change the final month or add a fifth row. Done means the final date remains 2024 for the original four-entry dataset.