Looking on the plugin page for Periodic Notes I found this:
Why the weekly note title is wrong with the week number?
Depending on your locale and operating system you are using, you may have been adopting either ISO week (first week of the year is started on the first Thursday) or Week of Year (first week of the year is started on the first day). Obsidian Periodic Notes uses Week of Year by default (ww), but you can change to ISO week by using (WW) instead. For more details, please refer to MomentJS documentation.
So it seems like (at least for me), the Calendar plugin is rendering using the Week of Year format, whereas everything else seems to be using the ISO week format. So the note names and all the links show week 29, whereas the calendar shows week 30.
I haven’t figured out how to change these so that it’s consistent everywhere.