Occurs in Fiber with multiple instances of the React package (which can't share current owner).
returnFiber: Fiber,
    newChild: any,
    priority: PriorityLevel,
  ): Fiber | null {
    if (typeof newChild === 'string' || typeof newChild === 'number') {
      
      
      
      const created = createFiberFromText(
        '' + newChild,
        returnFiber.internalContextTag,