Introducing Month field from Calendar changes YTD calculation

Then let's say you have a filter to limit to only July. Then your calculation is run in that context, thus finding the max year associated with July: 2018. 

If you want the max year from the calendar table, and ignore filters, you can do something like:

Sales YTD = 
var max_year = CALCULATE(MAX(Calendar2[Year]), ALL(Calendar2))
return CALCULATE([Ttl Sales],  //***Edit: Had forgotten to include "return"// 
FILTER(trans,year(trans[DATE])=max_year),
FILTER(trans,trans[Hold?]="n"))

Note: this is not a typical YTD function, as YTD usually refers to the cumulative value each month.