Problem with orders number

Hello, … (sorry for my english)

I have strange problem with Sequential Order Numbers PRO plugin.

Though in settings Prefix is set for “PL” Please look – prt cs – http://www.screencast.com/t/xCZeiVcN0O

In Orders, emails and everywhere we have orders with strange Prefix “##”

When i first time set for tests prefix “#” Now i cant’t change this.

Please look – http://www.screencast.com/t/Ixgs4B6vnH

Now we have problem with order tracking number….

Please tell me why it doesn’t work?

https://ww.wp.xz.cn/plugins/woocommerce-sequential-order-numbers/