Why I cannot apply existing tag to a prospect in the contact view

Hi all,

I am new to Infusionsoft and I would appreciate it if you can help me solve my problem.

I have created a number of tags when I just started, however, when I want to add them to a prospect, I cann

ot find some of the tags.

I’ve attached a video for your reference.

Thank you very much!

Regards,
Yixuan