Hashtags showing '0 posts' when uploading my own video

For example, when adding hashtags to my video before posting i wanted to add #vinlandsaga, but the list that automatically pop up and tells you how many posts use the hashtag is showing '0 posts'. This obviously isn't true since there are realistically atleast 100k videos with that tag. Does it mean the tag is temporarily down? Is my app glitched? Will i lose reach by using the tag anyway? Thanks.