Hi,
I checked the HikaMarket code and when you do delete a vendor through the HikaMarket backend interface, the vendor assignation on the user table is clean-up
You can check it yourself, you will see the query in the function "delete" of the HikaMarket vendor class.
So if you do not have the vendors anymore but you still have some values in the user table ; I have to suppose that you deleted the vendor directly in the database.
When you add a user to a vendor, you need to use the green button "add users" that we can see in your first screenshot.
The "save". It will add the line in the interface and the "save" will confirm the addition.
Before you do not provide the screenshot with the user in the "table" we could thought that you miss to click on that button before the save.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.