LTM policy to redirect uri to correct pool

I am trying to create a policy which redirect the request to correct pool based on URI. So i am trying to use a simple logic i.e. If uri starts with /help or /assistance at request time forward the traffic to POOL A at request time. Rest all traffic should go to default pool POOL B. In the VS default pool is configured POOL B. But it is not working for some reason & default traffic is also hitting the POOL A resulting 404 sometimes vice versa.

I also tried opposite mean if uri doesn't start with /help or /assistance redirect the traffic to POOL B at request time. Default pool in VS is POOL A. Still it is doing mix n match & creating 404 errors.

Can you please help me to understand if i need to create the default rule under policy? I am unable to find a knowledge article which describes how to add default rule which redirects all the default traffic to default pool.

So my policy looks like

If uri starts_with /help or /assistance --> Forward traffic to POOL A

Rest/default goes to POOL B

Thanks!