Network scan shows insecure wifi, open port. Contradicted by f-secure

[MrToad]

I did network scan on 2 laptops attached to my wifi network. I both cases avast indicated the internet had access due to open port..the router was insecure. To confirm, I ran well-regarded F-secure router checker  https://www.f-secure.com/en_US/web/home_us/router-checker and came up with "no issues found."
Since I'm not sure how to fix this router security problem if there is one, I need to confirm that avast is correct on this.

[Pondus]

Another opinion maybe? .... best of 3   

https://www.trendmicro.com/en_us/forHome/products/housecall.html

https://www.trendmicro.com/en_us/forHome/products/housecall/home-networks.html

[MrToad]

I used Steve Gibson's Shield's up https://www.grc.com/shieldsup to test both the port named by avast and all ports and no vulnerabilities were reported..I'm leaning toward Avast false positive on this.

[Pondus]

Be aware that when running grc test, it is testing the first firewall on the network ...
Is that your router? Are you behind a isp box with firewall ? Is your ISP blocking those ports,

Read all the info below after running grc test   

[MrToad]

I downloaded and ran housecall. Output was confusing...got they sense it was about promoting a product.