Term is not saved

Thank you for providing a plug-in. I installed and used this plug.
However,I couldn’t save the Taxonomy terms. In the existing check box of the post screen was able to be saved. Maybe, since the specification of wordpress has changed, I think in the destination has changed. The cause could not be found in my ability. Please tell me how to use.

https://www.ads-software.com/plugins/dbisso-cfs-taxonomy-field/