Thanks for the new assets file. It has the same wrong margin and pip cost as the old file - but only for USD/JPY. That's why you got a correct trade size with Z1.

Until this issue is solved, better stop Z1 too. Otherwise all USD/JPY trades will have a too small lot size.

For a next step: I suppose you also have an Oanda demo account. Please start Z7 on that demo account, wait until all assets are loaded, then stop it and upload the assets.csv again. I would like to check if the demo account produces the same wrong margin.