Steps to reproduce:
https://stats.wikimedia.org/#/en.wikipedia.org/reading/total-page-views/normal|bar|2021-06-01~2021-08-31|~total|monthly

Actual results:
The above graph for the three months June, July, and August 2021 has tree bars as expected, one for "Jun 2021", one for "Jul 2021", and one for "Aug 2021".
But the horizontal (time) axis has 9 tick marks with labels for "Jun 06", "Jun 13", "Jun 20", "Jun 27", "Jul 04", "Jul 11", Jul 18", "Jul 25", and "August", i.e. there are four tick marks for June, four for July, and one tick mark for August.
It is very confusing to have (some of the) tick marks on "week level" that are not even aligned to the montlhy bars.

Expected results:
When option "Monthly" is choosen, the tick marks and labels should not be on anything less than month level, , i.e. (at most) one tick mark/label for each bar in the diagram.
In the given example the horizontal (time) axis should just have three "tick marks" with labels for "Jun", "Jul", and "Aug"

Software version: Wikistats v2.9.1