Hi Thierry,
I’m sorry that you’re running into this issue! I took a look at the page you linked to, but the “next events” link appears to be working correctly for me (see screenshot) – were you able to get this resolved?
If not, what are you seeing when you try to click to the next month?
I would also recommend updating to the current versions of The Events Calendar (4.6.23) and Events Calendar Pro (4.4.32), as we just put out a maintenance release today. After updating, be sure to clear out your browser cache and any caching that you’re doing on your server/via a plugin, then try the links again.
Thanks,
Jennifer