WP Query order by meta_clause not working correctly for decimal values

[LordSpackolatius]

Short description: When using the WP 4.2 improvements for meta queries (as described here: ​https://make.wordpress.org/core/2015/03/30/query-improvements-in-wp-4-2-orderby-and-meta_query/) and trying to order the query by a decimal custom field, wordpress orders as if these fields are all integer and incorrectly handles all decimal values such as 1.5, 1.6 and 1.7 (all of these are seen as 1).

In detail:

WP_QUERY_ARGS Array
(
    [ignore_sticky_posts] => 1
    [post_status] => publish
    [offset] => 0
    [post_type] => Array
        (
            [0] => post
        )

    [orderby] => Array
        (
            [cf_clause_1] => DESC
            [ID] => ASC
        )

    [meta_query] => Array
        (
            [cf_clause_1] => Array
                (
                    [key] => my_decimal_custom_field
                    [type] => DECIMAL
                    [compare] => EXISTS
                )

        )

    [posts_per_page] => 10
    [nopaging] => 
)

5 Test posts:
Post 1 - my_decimal_custom_field = 1
Post 2 - my_decimal_custom_field = 2
Post 3 - my_decimal_custom_field = 2.2
Post 4 - my_decimal_custom_field = 2.6
Post 5 - my_decimal_custom_field = 3

Using the query above results in the order:
1,3,4,2,5

When it should be 1,2,3,4,5.

Trying out different order types as described in the WP Codex does not help.

[LordSpackolatius]

I made a small mistake with the 5 example posts:

Here is the correction:
Using the query above results in the order:
5,2,4,3,1
When it should be 5,4,3,2,1

[subrataemfluence]

A quick suggestion, might be useful!

What actual SQL query you get when you extract it using $query->request; and print it on screen? Does this outputs the query exactly as you want?

If yes, what you get when you run this query directly on your SQL query browser? Does this output the values in correct order?