If you create a post, add data for one or more ACF fields and then try to trash the post before having added any content or title, you’ll get an error.
Steps to replicate:
1) Create a new post
2) Add data for a custom field
3) Save draft or publish
4) Attempt to trash the post
Result: Error in moving the item to Trash.
If you don’t add any data to any custom fields and attempt to trash, it works as expected. Same if you add data to a custom field and also add something for the title or content, then trashing works as expected.
No PHP or WP errors are logged.
ACF Pro 6.3.1.2 on WP 6.5.4.