Opening balance in amortization schedule

[GINMED]

Hi, 

please help me to find correct way to calculate correct Opening balance = Previous period Closing balance.

There is my expectation:

There is my formula to calculate Opening Balance: 

OPEN_BAL =

VAR _PV = [PV]

var _Rate = MAX('Lig'[Rate in period])

var _Period = MAX('Lig_Project'[Seq])

var _AllPeriod = CALCULATE(max(('Lig_Project'[Seq])),ALLSELECTED('Lig_Project'),VALUES('Lig_Project'[PL Nr.]))

var _PMT = PMT(_Rate,_AllPeriod,_PV,0)

return

fv(_Rate,_Period-1,_PMT,_PV,0)*-1

But it doesn't give me correct result! Because there is specific issue with first interest payment, wich is correct amount given in table, and others Interest should be calculated.

Please, sombody help me to solve this issue!

There is my Power Bi sample

[lbendlin]

the link to the PBI file is private. Please check.

[GINMED]

Hi, @lbendlin 

there is my sample data

[lbendlin]

There is no link between Lig and Lig_Project.  Therefore PV will be blank.

[GINMED]

@lbendlin 

it doesn't affect to calculation. Lig_project is projected table from table Lig.