[Filtered Stream] URL of images are not returned

[ethielknd]

I have set the Stream configuration as follow:

opts := twitter.TweetSearchStreamOpts{
  TweetFields: []twitter.TweetField{twitter.TweetFieldEntities, twitter.TweetFieldCreatedAt},
  Expansions:  []twitter.Expansion{twitter.ExpansionAuthorID, twitter.ExpansionAttachmentsMediaKeys},
  UserFields:  []twitter.UserField{twitter.UserFieldProfileImageURL},
}

I receive the Media array by doing tweet.Raw.Includes.Media, but when I make a tweet with an image, the tweet.Raw.Includes.Media[0].URL is empty This is the log I got from tweet.Raw.Includes.Media[0]:

tweetIncludes.Media[0].AltText
tweetIncludes.Media[0].DurationMS 0
tweetIncludes.Media[0].Height 0
tweetIncludes.Media[0].Key 3_1712183042901491712
tweetIncludes.Media[0].NonPublicMetrics <nil>
tweetIncludes.Media[0].OrganicMetrics <nil>
tweetIncludes.Media[0].PreviewImageURL
tweetIncludes.Media[0].PromotedMetrics <nil>
tweetIncludes.Media[0].PublicMetrics <nil>
tweetIncludes.Media[0].Type photo
tweetIncludes.Media[0].URL
tweetIncludes.Media[0].Variants []
tweetIncludes.Media[0].Width 0

As you can see, tweetIncludes.Media[0].URL and tweetIncludes.Media[0].PreviewImageURL are empty, why is that?