Front / blocs order is not correct

[akossentini]

Sorting blocs in Backoffice is based on "orderVlaue" and calculated with
target.orderValue = (target.nextSibling () orderValue + target.previousSibling () orderValue..) / 2;
Somtimes, it gives orderValue with precision like "298.5".

In Frontoffice, API pages (get page from route) create an array with orderValue as indexes. "298.5" is not a valid index so it's placed at the end.
ksort ($ newBlocks);