The dog may be very clingy all of a sudden. It may be that he encountered some danger, which made him very scared and kept clinging to you. Even when it hasn't seen you for a long time, it will always stick to you. If it doesn’t recognize you as its master before, it will become clingy when it recognizes you as its master.

Tip:

Dogs are inherently clingy and need human companionship every day. If we don’t have much time to spend with dogs, it’s best not to keep them.