Calendar won't sync between devices

[Bethh29]

I can't get my Samsung calendar to sync between my Tab 6 lite and Note 20 ultra. 

I tap the "Sync now" on both devices, in the app, but nothing happens. 

I've gone into Samsung Cloud on my account, on my tablet but the calendar doesn't appear. It does appear on my phone cloud settings but when I tap "Sync now" nothing happens. 

[nowdeleted]

I use Google. Pc, laptop and 3 phones all get notifications

[Easty]

Think it was an issue for me before if the devices are on different one ui's

[-Robot-]

I use Google and the calendar is in sync not sure about Samsung Calendar