Firewall Blocking External Hard Drive

I cannot access my external hard drive unless I disable the firewall. It has worked fine for years and just started yesterday.

Disable port scanning in the firewall and check if the problem is solved.

where can I find that?

In the firewall settings.

opened avast, protection, firewall, settings. from there I have 4 tabs (polices, network profiles, friends, advanced). I don’t see anything about disabling port scanning anywhere.

Avast UI → Protection → Firewall → Settings → Advanced → Uncheck “Enable automatic port scan detection”