Team Calendar CalDav integration with iOS and macOS Catalina is not functioning correctly and does not reflect selected calendar colour

Problem

When subscribing with or adding an account from a Team Calendar in macOS Catalina. the macOS calendar app does not contain checkboxes to select these individual calendars. All Caldav calendars from confluence are also displayed with blank colours. Any colour changes made last only a few moments and then revert to blank or unset, the latest on the next start of the application. There is also a similar problem in iOS 13.4 with a slightly different behaviour and all colours change randomly on reload.

Environment

MacOS Catalina
iOS 13.4

Steps to Reproduce

• Create a Team Calendar in Confluence with multiple calendars
• Choose to subscribe to this calendar and either choose your app as Apple Calendar (MacOS) or Apple Calendar (iOS)
• Add a new account or subscribe to the Caldav calendar in MacOS/iOS calendar.
• Open the calendar app

Expected Results

Team Calendars should behave in the same manner as other Caldav calendars in the app

Actual Results

Team Calendar Caldav calendars do not contain checkboxes to select the individual calendars when uncoloured and they are also displayed with blank checkboxes, any attempt to colour them is reset again after a few seconds or when opening the app.

Workaround

No workaround is currently available

Notes

This does not occur in MacOS Mojave
Other Caldav calendar hosts do work correctly, Nextcloud and Owncloud Caldav calendars behave as expected.