Extra number added automatically

[Westlifers]

I followed your steps and correctly did all settings. Everything worked well, but the sequence number before the footnote

There are extra number appears before every footnote and even caused overflow.
I tried the demo and the same phenomenon appeared. Wondering how to fix this.
P.S. I'm using the theme Volantis, no more plugins installed.

[Huster1993]

the same mistake