Update a user’s preference via a link - not working

Hi, I am trying to use the following variable via a button in an email:

{% preference_link 'customer_type' 'gen_cust' %}

As described here: https://help.klaviyo.com/hc/en-us/articles/4408802648731-Guide-to-Template-Tags-and-Variable-Syntax-new-editor-#manage-preferences8

When I send a test email and click the button, I am directed to my “update preferences” page, however, the custom property specified is not updated with the specified value 

Both ‘customer_type’ and ‘gen_cust’ are both properties that exist on my manage preference page. What am I doing wrong?

If i use the variable {% update_property_link 'customer_type' 'gen_cust' 'www.hsconline.co.uk' %} in the button URL instead, then the property value on the profile is updated, however, I need the customer to end up on their update preferences page rather than my home page.

What am I doing wrong with the {% preference_link 'customer_type' 'gen_cust' %} variable?

Is there a way to use the {% update_property_link 'customer_type' 'gen_cust' 'www.hsconline.co.uk' %} variable but end up on the customers update preferences page rather than'www.hsconline.co.uk'?

Thanks