I’ve tried looking into why this is and it doesn’t seem to come up very often. As soon as I plugged in my router, I changed the router password to a 30-character symbol-ridden monstrosity. However, after connecting all of my devices, my phone claimed that my router password was weak. I tried logging into my router using the default credentials and a couple things that might also be standard. Nothing got me in.
It seems that because I have a password recovery option enabled, Wi-Fi finder flags my router as having a weak password (I turned it off and it showed my router as safe). Is this by design? If so, it should probably be more clear about why it’s flagging my router because my password is definitely NOT weak! I should also point out that the recovery option requires the router’s serial number before I have access to the two social-engineering-could-conceivably-get-the-answers questions.
Please reconsider flagging routers as having a weak password if they have password recovery turned on if this is the case. If not, well then there’s a bug, as it should certainly not be flagging my password as “weak.”