please always use the following code to store images in the database
->usingName(uniqid('collection-image-', true))
->usingFileName(uniqid('collection-image-', true) . '.' . pathinfo($this->fileUrl, PATHINFO_EXTENSION))
like in the following example
$collection->addMediaFromUrl($request->fileUrl)
->usingName(uniqid('collection-image-', true))
->usingFileName(uniqid('collection-image-', true) . '.' . pathinfo($this->fileUrl, PATHINFO_EXTENSION))
->toMediaCollection('collection-images');