MikroTik admin (port 8291) is open

In short: If you run a MikroTik router, close its admin port to the internet.

What this means

Port 8291 is the Winbox admin port on MikroTik routers. It is meant for you, not for the internet, and older software versions have had serious flaws.

What to do

In RouterOS, open IP, Firewall and add a rule that drops traffic to port 8291 arriving from the internet side.
Under IP, Services, disable services you do not use, or limit them to your home addresses.
Update RouterOS and change any default admin password.

If you do not own a MikroTik router, ask whoever set up your network. This can be a sign of a router you did not know about.

Then check again

Run the free check after you make a change. An A or B only means nothing risky is visible from the internet. It does not mean every device in your home is safe, so keep phones, TVs and computers on automatic updates.

Run the free check

Not sure about a step, or this is a work or rented network? Ask whoever manages it before changing settings.