diff --git a/src/platform/nrf52/main-nrf52.cpp b/src/platform/nrf52/main-nrf52.cpp
index f7b3a7d9a..f120d387c 100644
--- a/src/platform/nrf52/main-nrf52.cpp
+++ b/src/platform/nrf52/main-nrf52.cpp
@@ -378,7 +378,11 @@ void nrf52Setup()
     pinMode(ADC_V, INPUT);
 #endif
 
-    uint32_t why = NRF_POWER->RESETREAS;
+    // The Adafruit core's init() (cores/nRF5/wiring.c) caches RESETREAS into a static and then
+    // W1C-clears the hardware register before setup() ever runs, so a raw NRF_POWER->RESETREAS
+    // read here is ALWAYS 0. Use the core's cached copy so this log line is actually meaningful
+    // (0x1 pin reset, 0x2 watchdog, 0x4 soft reset/SREQ, 0x8 CPU lockup, 0x10000 System OFF wake).
+    uint32_t why = readResetReason();
     // per
     // https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52832.ps.v1.1%2Fpower.html
     LOG_DEBUG("Reset reason: 0x%x", why);
diff --git a/variants/nrf52840/nrf52.ini b/variants/nrf52840/nrf52.ini
index 76e3191b4..f989a48a4 100644
--- a/variants/nrf52840/nrf52.ini
+++ b/variants/nrf52840/nrf52.ini
@@ -23,6 +23,13 @@ build_flags =
   ${arduino_base.build_flags}
   -Wno-unused-variable
   -Isrc/platform/nrf52
+  ; The Arduino loop task runs the entire cooperative OSThread scheduler; the core's stock
+  ; 4 KB (1024-word) stack overflows during BLE first-sync (admin config-apply -> radio
+  ; reconfigure with XEdDSA/satmap/log frames stacked) - SWD-proven on T1000-E: SP driven
+  ; 40 B below pxStack, corrupting adjacent heap -> silent HardFault reset on phone pairing.
+  ; 2048 words = 8 KB, validated on hardware. Value is in WORDS; requires the #ifndef guard
+  ; from meshtastic/Adafruit_nRF52_Arduino#7 (harmless redefinition warning until it merges).
+  -DLOOP_STACK_SZ=2048
   -DLFS_NO_ASSERT                      ; Disable LFS assertions , see https://github.com/meshtastic/firmware/pull/3818
   -DMESHTASTIC_EXCLUDE_AUDIO=1
   -DMESHTASTIC_EXCLUDE_PAXCOUNTER=1