A small percentage in another language is normal and some followers are only interested in the posts or pictures. However, if the majority of the followers are from another country, then it rather indicates that either the influencer used to post in another language and then changed the language.
For example, we often see that influencers used to post in English and then later switched to German to be more attractive for advertising campaigns. The English part of the followers then remains. Another reason can be an unnatural way of gaining followers, such as buying fake followers or following/unfollowing. We generally recommend approaching the influencer and seeking a conversation. Many influencers are transparent and can often provide an insightful explanation.