Hi Damien!
Just wanted to share with you that a new release of our plugins is out, including a fix for this issue 🙂
Find out more about this release → https://theeventscalendar.com/maintenance-release-for-the-week-of-30-september-2018/
Please bear in mind that if you currently have recurring events with this problem, you will need to re-save them after this update so that the series regenerates correctly.
We apologize for the delay and appreciate your patience while we worked on this.
As always, we suggest to setup a dev/staging site so you can make all plugin updates without disrupting the live site.
Please update the plugins and let us know if the fix works for your site.
Best,
Victor