diff --git a/Lib/fontTools/varLib/instancer.py b/Lib/fontTools/varLib/instancer.py
index 2f92157b0..c3d342433 100644
--- a/Lib/fontTools/varLib/instancer.py
+++ b/Lib/fontTools/varLib/instancer.py
@@ -419,8 +419,8 @@ def _featureVariationRecordIsUnique(rec, seen):
     conditionSet = []
     for cond in rec.ConditionSet.ConditionTable:
         if cond.Format != 1:
-            # can't tell whether this is duplicate, assume not seen
-            return False
+            # can't tell whether this is duplicate, assume is unique
+            return True
         conditionSet.append(
             (cond.AxisIndex, cond.FilterRangeMinValue, cond.FilterRangeMaxValue)
         )
@@ -474,6 +474,7 @@ def _instantiateFeatureVariations(table, fvarAxes, location):
                 )
                 applies = False
                 newConditions.append(condition)
+                break
 
         if retainRecord and newConditions:
             record.ConditionSet.ConditionTable = newConditions
diff --git a/Tests/varLib/instancer_test.py b/Tests/varLib/instancer_test.py
index 9fead7ab4..2c418697a 100644
--- a/Tests/varLib/instancer_test.py
+++ b/Tests/varLib/instancer_test.py
@@ -1285,9 +1285,8 @@ class InstantiateFeatureVariationsTest(object):
     def test_unsupported_condition_format(self, varfont3):
         gsub = varfont3["GSUB"].table
         featureVariations = gsub.FeatureVariations
-        cd = featureVariations.FeatureVariationRecord[0].ConditionSet.ConditionTable[0]
-        assert cd.Format == 1
-        cd.Format = 2
+        rec1 = featureVariations.FeatureVariationRecord[0]
+        rec1.ConditionSet.ConditionTable[0].Format = 2
 
         with CapturingLogHandler("fontTools.varLib.instancer", "WARNING") as captor:
             instancer.instantiateFeatureVariations(varfont3, {"wght": 0})
@@ -1296,3 +1295,6 @@ class InstantiateFeatureVariationsTest(object):
             r"Condition table 0 of FeatureVariationRecord 0 "
             r"has unsupported format \(2\); ignored"
         )
+
+        # check that record with unsupported condition format is kept
+        assert featureVariations.FeatureVariationRecord[0] is rec1