diff --git a/esphome/components/mdns/mdns_esp8266.cpp b/esphome/components/mdns/mdns_esp8266.cpp
index f8ef014b09..cd2ae8ef97 100644
--- a/esphome/components/mdns/mdns_esp8266.cpp
+++ b/esphome/components/mdns/mdns_esp8266.cpp
@@ -87,10 +87,13 @@ void MDNSComponent::start_polling_window_() {
   // uint32_t-ID set_interval/set_timeout already does atomic cancel-and-add.
   this->set_interval(MDNS_POLL_ID, MDNS_UPDATE_INTERVAL_MS, []() {
 #ifdef USE_MDNS_WIFI_LISTENER
-    // Every send fails while the radio is off channel or no interface is up, and each one
-    // spins sendTimeout() for 50 ms; skip the tick rather than stall the loop for nothing.
+    // MDNS.update() can suspend the loop in UdpContext::sendTimeout() while a send is
+    // failing (radio off-channel during a roam scan, or mid reconnect); an incoming
+    // packet then re-enters LEAmDNS from lwIP and corrupts shared UdpContext state.
+    // Skip the tick while the radio cannot transmit (#18760), but keep polling while
+    // the AP is serving clients (AP-only or fallback AP with the STA down).
     auto *wifi = wifi::global_wifi_component;
-    if (wifi->is_roaming_scan_active() || (!wifi->is_connected() && !wifi->is_ap_active()))
+    if (wifi->is_roaming() || (!wifi->is_connected() && !wifi->is_ap_active()))
       return;
 #endif
     mdns_responder.update_guarded();