Wrong month

Hello there

First of all I want to give my compliments to make such a great plugin!

However I’m experiencing a problem with the layout since today. The grid view isn’t correct because April is still showing when opening the page however it’s May the first. I did take a look on other topics and saw that someone discribed the same problem (https://wordpress.org/support/topic/grid-view-start-month-wrong/). So I started checking the dates in WordPress itself and experimenting with the custom field in the plugin, but no success.

Is there anything I can do to fix this?

Thanks for your help!