There is no error in my browser console.
Apparently I did not express my intention.
I’m sorry that my English is not good.
More explanation:
In your forum, go to the profile option to set the signature. When you click on the Update Signature Nothing will be displayed to you during signature setting. Only when the signature is set will you be notified.
During the time of the signature setting(post setting and server response by ajax), the “saving… message” will not be displayed. Like when the post is sent.
The following video is provided by your own forum
https://vimeo.com/230154366