PHP Warning: Undefined array key 0 in /app/wp-includes/meta.php on line 674 is emitted to console. the parameters it is given are:

$check = apply_filters( "get_{$meta_type}_metadata", null, $object_id, $meta_key, $single, $meta_type );

meta_type: user
meta_key: simple_local_avatar
single: 1
object_id: 2

the value of the filter returns ($check) an empty array, but, the wordpress code returns the first element (0), which is thus undefined.

this causes a bunch of undefined key errors to console.

this is with wordpress 6.9 (and perhaps older).