The well-known ZACKBUKS filter has informed about the pre-order volume of the expensive new flagship Sony Xperia 1 IV. According to this source, the volume of units sold in the reservation period probably reaches “only a third of last year’s Xperia 1 III.” The price of the Xperia 1 IV is hefty whatever the market ($1,599.99/€1,399/£1,299), though there could be other reasons why pre-orders for this device are suffering. The popular Chinese distributor JD.com has more than 32,000 customers who seem to have booked the Sony Xperia 1 IV. That figure is very small compared to, for example, the Xiaomi…