Hey there,
and thanks for your message.
There was a bug prior version 2.24.0 which caused an issue using arrows in the textfield of the Postmeta field type. So I would recommend up upgrade to the latest version first.
If the problem still persists, please post the structured of the array from the database.
Also please note that the data needs to be stored in the wp_postmeta database table. SNIP cannot access data from anywhere else at this point in time.
Greetings
Flo