iCloud syncing issues - Notes

We use the notes app a lot.

Sharing between my partner and myself.

Adding and modifying notes on my iPad Pro, iPhone 13 and MacPro(2019).

But I'm having bad syncing issues.

Let's get this out of the way:

• yes OS software up to date on all devices.
• yes it is using the same iCloud account
• yes iCloud is turned on for Notes on all devices
• it used to work before, now it does not.

If I add a new note, modify a note, add photos, delete a note or share a note on my iPhone or iPad, the note shows up everywhere else as it should.

But, on my MacPro if add a new note, modify a note, add photos, delete a note or share a note, nothing changes on the other devices.

This is new behaviour and it's pretty frustrating.