diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatTokens.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatTokens.scala
index f91f85b264..64db04daaf 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatTokens.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/FormatTokens.scala
@@ -158,14 +158,17 @@ class FormatTokens(leftTok2tok: Map[TokenHash, Int])(val arr: Array[FormatToken]
     getClosingIfInParens(last)(getHead(tokens, tree)).getOrElse(last)
   }
 
-  @tailrec
   final def findTokenWith[A](ft: FormatToken, iter: FormatToken => FormatToken)(
       f: FormatToken => Option[A],
+  ): Either[FormatToken, A] = findTokenEx(ft)(xft => f(xft).toRight(iter(xft)))
+
+  @tailrec
+  final def findTokenEx[A](ft: FormatToken)(
+      f: FormatToken => Either[FormatToken, A],
   ): Either[FormatToken, A] = f(ft) match {
-    case Some(a) => Right(a)
-    case _ =>
-      val nextFt = iter(ft)
-      if (nextFt eq ft) Left(ft) else findTokenWith(nextFt, iter)(f)
+    case null => Left(ft)
+    case Left(nextFt) if nextFt ne ft => findTokenEx(nextFt)(f)
+    case x => x
   }
 
   final def findToken(ft: FormatToken, iter: FormatToken => FormatToken)(
diff --git a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala
index 2cb1803625..61bd0e6784 100644
--- a/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala
+++ b/scalafmt-core/shared/src/main/scala/org/scalafmt/internal/Router.scala
@@ -1205,9 +1205,6 @@ class Router(formatOps: FormatOps) {
           flags.literalArgList
         val nlOnly = nlOpen && !singleLineOnly
 
-        def findComma(ft: FormatToken) = findFirstOnRight[T.Comma](ft, close)
-          .map(_.right)
-
         val binPack = style.binPack.callSiteFor(open)
         val oneline = binPack.isOneline
         val afterFirstArgOneline =
@@ -1266,7 +1263,15 @@ class Router(formatOps: FormatOps) {
               else Seq(indent)
 
             val nextComma =
-              if (!oneline) findComma(ft)
+              if (firstArg.isEmpty) None
+              else if (!oneline) tokens.findTokenEx(ft) { xft =>
+                xft.right match {
+                  case `close` | _: T.RightBrace | _: T.RightArrow => null
+                  case x: T.Comma => Right(x)
+                  case x: T.LeftBrace => Left(tokens(matching(x)))
+                  case _ => Left(next(xft))
+                }
+              }.toOption
               else if (isSingleArg) None
               else afterFirstArgOneline.map(_.right)
             val opt = nextComma.getOrElse(scalaJsOptClose(beforeClose, flags))
diff --git a/scalafmt-tests/shared/src/test/resources/scalajs/Apply.stat b/scalafmt-tests/shared/src/test/resources/scalajs/Apply.stat
index e9358512d3..a27ae548f4 100644
--- a/scalafmt-tests/shared/src/test/resources/scalajs/Apply.stat
+++ b/scalafmt-tests/shared/src/test/resources/scalajs/Apply.stat
@@ -1403,3 +1403,15 @@ object a {
     varDefs.take(prevArgsCount).toList.map(_.ref))(
     sym, index, formalArgsRegistry, param, static, captures = Nil)
 }
+<<< #4133 overflow with nested lambda and braces 1
+Block(norm.tail.map(sym => DefDef(sym, { vparamss: List[List[Symbol]] => EmptyTree })), ddef)
+>>>
+Block(norm.tail.map(sym =>
+      DefDef(sym, { vparamss: List[List[Symbol]] => EmptyTree })), ddef)
+<<< #4133 overflow with nested lambda and braces 2
+other.exists(tpe match { case TypeRef(_, r, _) => r.isTypeParameter case _ => false })
+>>>
+other.exists(tpe match {
+  case TypeRef(_, r, _) => r.isTypeParameter
+  case _                => false
+})