Hi,
assuming you ask for AWAF signatures - update all of them regularly. They contain signatures to protect you from current threats.
You can subscribe here: https://interact.f5.com/Customer-Preference-Center.html
And you will get notifications about new Threat Campaign and Bot signature update releases, as well as ASM attack signature update releases
Also, updated signatures won't block anything immediately:
K04853200: How updated ASM attack signatures are enforced
And also see:
K82512024: Managing BIG-IP ASM Live Updates (14.1.x and later)
KR
Daniel