I’ve actually solved the problem already (by changing the translation, as mentioned above). I just wanted to alert you of the cause of the problem. Although the real root of the problem seems to be that there is no page at the URL with the translated month in it.
If it is of interest, this is the URL that gives me the 404: https://glco.org/events/monat/
Again, it’s solved for me because I changed the ‘monat’ slug to ‘month’ in string translation. Now everything works when switching between list and month views.
