Quality Source Data

talbrechtsen , You need follow a approch like this

Customer Retention Part 5: LTD Vs Period Retention
https://community.powerbi.com/t5/Community-Blog/Customer-Retention-Part-5-LTD-and-PeriodYoY-Retention-is-only/ba-p/2114497

Lost is what you are looking at , Duration can rolling 12 oe before or this year and before

example measures

rolling 12 =
var _max = if(isfiltered('Date'),MAX( 'Date'[Date]) , today())
var _min = date(Year(_max), month(_max) -12, Day(_max))+1
BLANK())
return
CALCULATE([net] ,DATESBETWEEN('Date'[Date],_min,_max))

LTD =
var _max = if(isfiltered('Date'),MAX( 'Date'[Date]) , today())
var _min = Minx(ALLSELECTED('Date'),'Date'[Date])
return
CALCULATE([net] ,DATESBETWEEN('Date'[Date],_min,_max))

LTD before 12 =
var _max1 = if(isfiltered('Date'),MAX( 'Date'[Date]) , today())

var _max = date(Year(_max1), month(_max1) -12, Day(_max1))
var _min = Minx(ALLSELECTED('Date'),'Date'[Date])
return
CALCULATE([net] ,DATESBETWEEN('Date'[Date],_min,_max))

YTD =
var _max = if(isfiltered('Date'),MAX( 'Date'[Date]) , today())
var _min = eomonth(_max,-1*MONTH(_max))+1
return
CALCULATE([net] ,DATESBETWEEN('Date'[Date],_min,_max))

LTD before This year =
var _max1 = if(isfiltered('Date'),MAX( 'Date'[Date]) , today())

var _max = eomonth(_max,-1*MONTH(_max))
var _min = Minx(ALLSELECTED('Date'),'Date'[Date])
return
CALCULATE([net] ,DATESBETWEEN('Date'[Date],_min,_max))