Avast scan says my router is accessible from the internet

My modem control web page is different from ALL the ones you list so i can’t fix it, i wish i’d never run the scan, rather be blissfully ignorant, now what? You (perhaps) correctly detected it is ZyXEL PK5001Z although you call it “PK5001Z.PK5001Z” so perhaps the extra “.PK5001Z” is wrong???
Under HNS-WAN-ACCESS click Zyzel logo Step 3 says “Go to Expert Mode …”
Wrong. I do have “Advanced Setup” and under that “Remote GUI” and “Remote Console” and are both DISABLED.

Not too impressed with Avast yet.

Is your router admin log in name and password factory default?