Attachments in Locked notes lost!

I save a lot of attachments into notes such as PDFs, screenshots etc and for sensitive information such as banking details etc, I lock them. To my horror, most of these are now not there anymore. I either have a small thumbnail but that's all and can't view that thumbnail anymore at full size or I have a blank space where I would of previously had the attachment. It seems to be an issue that is only happening to locked notes specifically. The affected notes are the same both on my Mac and iPhone and the same issue whether I'm on 3G/Wifi etc.

I should also say that some of the attachments show up as 'LOADING' but nothing ever loads.

Has anyone else come across this? I am using a macOS Monterey 12.6 and iOS 16.02.