Apple Calendar not synching with Google calendar

Hello, While the descriptive title is correct, it is not entirely accurate. Due to multiple reasons my scheduling requirements are a little more complex than most. In reality I do not actually use Google calendar for scheduling, as I work with multiple devices. The Google calendar would be more accurately defined as a synchronisation hub for the various calendar apps I use regularly. My primary calendar application would be Samsung calendar, secondary Microsoft Outlook and so on. Google calendar is working as expected any appointments created within any of my scheduling apps (excluding Apple calendar) are being displayed within all my calendars (including Apple calendar), but any appointments created within the Apple calendar are not being displayed in application other than the Apple calendar application. As you can imagine this is causing some scheduling issues for me. As an aside can also remark that any appointment made within the Apple calendar is also not being shown on the Google calendar app installed on my iPhone or iPad