Preserve netmask if one isn't supplied in address

src/data/hassio/network.ts

@@ -117,11 +117,10 @@ export const accesspointScan = async (
 };
 
 export const parseAddress = (address: string) => {
-  const isIPv6 = address.includes(":");
-  const [ip, cidr] = address.includes("/")
-    ? address.split("/")
-    : [address, isIPv6 ? "64" : "24"];
-  return { ip, mask: cidrToNetmask(cidr, isIPv6) };
+  const [ip, cidr] = address.split("/");
+  const isIPv6 = ip.includes(":");
+  const mask = cidr ? cidrToNetmask(cidr, isIPv6) : null;
+  return { ip, mask };
 };
 
 export const formatAddress = (ip: string, mask: string) =>

src/panels/config/network/supervisor-network.ts

@@ -655,8 +655,14 @@ export class HassioNetwork extends LitElement {
     this._dirty = true;
     if (id === "address") {
       const index = (ev.target as any).index as number;
+      const { mask: oldMask } = parseAddress(
+        this._interface![version]!.address![index]
+      );
       const { mask } = parseAddress(value);
-      this._interface[version]!.address![index] = formatAddress(value, mask);
+      this._interface[version]!.address![index] = formatAddress(
+        value,
+        mask || oldMask || ""
+      );
       this.requestUpdate("_interface");
     } else if (id === "netmask") {
       const index = (ev.target as any).index as number;