I just wanted to add that I solved another problem with multiple calendars on my wint.global cPanel Horde accounts.
When I setup different calendars from multiple accounts, they didn’t show up on the Android calendar app. They all had the same color and the same name. I don’t know if that was the reason, but I could rename them and give them individual colors in Horde. Then I deleted and recreated the accounts on Davdroid. After that I went into the settings in the calendar app. There I could find the calendars.
