@lubos have generated a report of Inventory costing worksheet to reconcile the average cost on Inventory Tab. I noted that the two average cost shows different values. In my opinion, the average cost should match. It will be appreciated if @lubos take a look into the issue.
The screenshot is appended below for review:
INVENTORY COSTING CALCULATION WORKSHEET
INVENTORY ITEM TAB
The good thing is that the quantity match but total cost don’t match
According to your screenshots, your two examples use different costing methods.
As i see, the difference is not due to different costing method. It is the total cost which may be yielding different value of average cost.
Further, even if use different costing method how could the unit average cost has this big difference. A little difference could be accepted.
On your observation. I generated a report again based on the same costing methods. Yes, the two reports are now showing same average cost. Thanks @Tut for identifying the problem 
Because average cost takes into account the entire previous purchasing history for the inventory item. The average cost of those items remaining in inventory could be increased or decreased by the purchase cost of units already sold. FIFO alters that history by removing items already sold and costing only those remaining in inventory. This is the most fundamental difference between the two costing methods.
No, it should be expected. This is why businesses may be able to make a profit selling old stock at lower prices—it was purchased for less than it can now be replaced.
i also have same problem like this. the avg cost is different and causing big problem. the net income become double . i already recalculate all inventory items, but still wrong amount.
It seems that the inventory problems will return.
I do not know why the insistence on using the periodic inventory system.
I have recently noticed that the purchasing operations calculate the average cost based on the perpetual inventory system and sometimes the calculation is not done, and the recalculation has been recalculated to make adjustments if any but the manager re-adjusts based on the periodic inventory system.
I also have the same Issue (I’m using desktop version), I’ve noticed these difference in my Inventory average cost after installing a new update version a couple weeks ago.
Your two examples use different costing methods, as shown in your screenshots. However, there are some differences between them.
