rewrite directive in valets nginx.conf is not working

Hi everbody, in a nginx config file on my linux server I use the following directive in the server blocks (one for http and one for https) for my css and js files:

rewrite ^/cache-buster-(?:\d+)/(.*) / last;

and there it is working just as it should. It just removes the "cache-buster- ..." part and then links to the app.css or app.js files. Now on my local machine with valet I have a config file in ~/.config/valet/Nginx/mylocalsite.test and there the above directive does not rewrite anything. And I have no clue what is going wrong. There is no entry in the error.log file and in the access.log it just states that the files /cache-buster-2342134.app.css, etc. cannot be found, off course not. Is this somehow related to valet, or what am I missing?

thank you in advance.