Identifying ASM signatures affecting responses?

Response Signatures do not modify the response. They DETECT an attack and raise the violation. You need to look at ASM features affecting the response as per my response here:

https://devcentral.f5.com/questions/any-experience-with-asm-policy-affecting-response-stream-with-no-vulnerability-attack-signature-noted-61426?

it is also worth raising a support case with F5