Based Currency and Purchasing Currency are not same, there was freight charges
Version : 22.1.52
Purchase Price were same, but average costing were not same when we used foreign currency.
Purhcase Price 3.99 Euro
Average Cost 12609.75 vs 12634.14 (same purchase invoice, just bought, no others transactions yet)
The average cost is correct, but you do not understand how Manager calculates the cost
The process is explained in the Freight Cost guide
The average cost is the result of all previous purchases and sales, so you need to look at the full history of the inventory item from the first purchase
As others say that is not how it works with Manager forum. There are many users that could help you. Most of us like @Joe91 will not help until you post it here in the forum.
Whatever your first post shows it is not from Manager
The average costs calculated by Manager (21,320 and 21,310 ) are exactly what they should be, bearing in mind minor rounding differences introduced by the use of the exhange rate 1 MMK = 0.0005 euro