See below:

import scala.util.matching.Regex

object DemoRegex extends App {
  
  val yearExt = """CAL(\d{2})""".r
  val yearExt(year) = "CAL12"
    // after hitting ENTER on previous line the cursor is not aligned properly
    // it is not under v
    
  val yearExt(year2) = {"CAL12"}
  // now cursor is aligned properly!
  // it is under v!
}

I suspect it gets confused by the parentheses () on the lhs.

Thanks,
Tony

val x = "abc"
  // indented