Visibility per php-code

I'm searching for a possibility to trigger visibility by taxonomy term, like "show only when php-code is true".

Now I use wildcard * and then I restrict visibility in the block's menu with: "show only ... php-code True". This works.

The problem: When I edit anything in the node, saving overrides the visibility in the block's menu with the default wildcard *. Could I get rid of this?

Any help would be appreciated.