Split fixed asset functionality in D365 does not split the asset quantity. After the asset split is posted, the original asset quantity is retained in the old(original) asset and the new asset is assigned with the shared quantity from the old asset, hence overstating the total asset quantity in the record.

It is a common scenario for companies to split their fixed assets, which means splitting the value and the quantity. The complication with the current design is that in case a split has been made with the intention of disposing portion of the assets, but the disposal is done in the next year, at the end of the current year, the quantity of fixed assets is overstated.