fixes #21263; consider all candidates for concept matches (#21265)

tests/concepts/tconcepts_issues.nim

@@ -27,6 +27,8 @@ false
 true
 -1
 Meow
+10 0.0
+1 2.0
 '''
 joinable: false
 """
@@ -500,3 +502,26 @@ var r, b: Fp2[6, uint64]
 
 prod(r, b)
 
+
+block: # bug #21263
+  type
+    DateDayFraction = concept # no T, an atom
+      proc date(a: Self): int
+      proc fraction(b: Self): float
+    Date = distinct int
+    DateDayFractionImpl = object
+      date : int
+      fraction : float
+
+  proc date(a: Date): int = a.int
+  proc fraction(a:Date): float = 0.0
+
+  proc date(a: DateDayFractionImpl): int = a.date
+  proc fraction(b: DateDayFractionImpl): float = b.fraction
+
+
+  proc print(a: DateDayFraction) =
+    echo a.date, " ", a.fraction
+
+  print(10.Date) # ok
+  print(DateDayFractionImpl(date: 1, fraction: 2))  # error