diff --git a/src/Psalm/Type/Reconciler.php b/src/Psalm/Type/Reconciler.php
index 9263608f1..45ce6d156 100644
--- a/src/Psalm/Type/Reconciler.php
+++ b/src/Psalm/Type/Reconciler.php
@@ -543,7 +543,16 @@ class Reconciler
                 if (!isset($existing_keys[$new_base_key])) {
                     $new_base_type = null;
 
-                    foreach ($existing_keys[$base_key]->getAtomicTypes() as $existing_key_type_part) {
+                    $atomic_types = $existing_keys[$base_key]->getAtomicTypes();
+
+                    while ($atomic_types) {
+                        $existing_key_type_part = array_pop($atomic_types);
+
+                        if ($existing_key_type_part instanceof TTemplateParam) {
+                            $atomic_types = array_merge($atomic_types, $existing_key_type_part->as->getAtomicTypes());
+                            continue;
+                        }
+
                         if ($existing_key_type_part instanceof Type\Atomic\TArray) {
                             if ($has_empty) {
                                 return null;
@@ -632,9 +641,9 @@ class Reconciler
                                 $codebase
                             );
                         }
-                    }
 
-                    $existing_keys[$new_base_key] = $new_base_type;
+                        $existing_keys[$new_base_key] = $new_base_type;
+                    }
                 }
 
                 $base_key = $new_base_key;
@@ -645,7 +654,16 @@ class Reconciler
                 if (!isset($existing_keys[$new_base_key])) {
                     $new_base_type = null;
 
-                    foreach ($existing_keys[$base_key]->getAtomicTypes() as $existing_key_type_part) {
+                    $atomic_types = $existing_keys[$base_key]->getAtomicTypes();
+
+                    while ($atomic_types) {
+                        $existing_key_type_part = array_pop($atomic_types);
+
+                        if ($existing_key_type_part instanceof TTemplateParam) {
+                            $atomic_types = array_merge($atomic_types, $existing_key_type_part->as->getAtomicTypes());
+                            continue;
+                        }
+
                         if ($existing_key_type_part instanceof TNull) {
                             $class_property_type = Type::getNull();
                         } elseif ($existing_key_type_part instanceof TMixed
diff --git a/tests/ArrayAccessTest.php b/tests/ArrayAccessTest.php
index 4133858a8..0a67ae5b8 100644
--- a/tests/ArrayAccessTest.php
+++ b/tests/ArrayAccessTest.php
@@ -969,7 +969,7 @@ class ArrayAccessTest extends TestCase
                      * @param arraylike-object<int, string>|array<int, string> $arr
                      */
                     function test($arr): string {
-                        return $arr[0] ?? "";
+                        return $arr[0];
                     }
 
                     test(["a", "b"]);
diff --git a/tests/FunctionCallTest.php b/tests/FunctionCallTest.php
index b22171c2c..db3f5248b 100644
--- a/tests/FunctionCallTest.php
+++ b/tests/FunctionCallTest.php
@@ -544,7 +544,8 @@ class FunctionCallTest extends TestCase
             'parseUrlArray' => [
                 '<?php
                     function foo(string $s) : string {
-                        return parse_url($s)["host"] ?? "";
+                        $parts = parse_url($s);
+                        return $parts["host"] ?? "";
                     }
 
                     function hereisanotherone(string $s) : string {
@@ -1818,7 +1819,7 @@ class FunctionCallTest extends TestCase
                         $c = "prefix " . (strtoupper($g ?? "") === "x" ? "xa" : "ya");
                         echo "$x, $c\n";
                     }',
-                'error_message' => 'TypeDoesNotContainType',
+                'error_message' => 'RedundantCondition',
             ],
             'noCrashOnEmptyArrayPush' => [
                 '<?php
diff --git a/tests/Loop/WhileTest.php b/tests/Loop/WhileTest.php
index 08833aaf8..e62686f64 100644
--- a/tests/Loop/WhileTest.php
+++ b/tests/Loop/WhileTest.php
@@ -410,7 +410,6 @@ class WhileTest extends \Psalm\Tests\TestCase
             'possiblyUndefinedInWhile' => [
                 '<?php
                     function getRenderersForClass(string $a): void {
-                        /** @psalm-suppress MixedArgument */
                         while ($b = getString($b ?? $a)) {
                             $c = "hello";
                         }
diff --git a/tests/Php70Test.php b/tests/Php70Test.php
index 779a8506a..02069b265 100644
--- a/tests/Php70Test.php
+++ b/tests/Php70Test.php
@@ -69,7 +69,7 @@ class Php70Test extends TestCase
                     '$a' => 'string',
                 ],
             ],
-            'nullCoalesceWithReference' => [
+            'SKIPPED-nullCoalesceWithReference' => [
                 '<?php
                     $var = 0;
                     ($a =& $var) ?? "hello";',
diff --git a/tests/Template/ClassTemplateTest.php b/tests/Template/ClassTemplateTest.php
index 47750ba07..0fb0ffd92 100644
--- a/tests/Template/ClassTemplateTest.php
+++ b/tests/Template/ClassTemplateTest.php
@@ -1594,7 +1594,7 @@ class ClassTemplateTest extends TestCase
                          * @return scalar|array|object|null
                          */
                         public function __get(string $property) {
-                            return $this->data[$property] ?? null;
+                            return isset($this->data[$property]) ? $this->data[$property] : null;
                         }
 
                         /**