diff --git a/app/static/js/app.jsx b/app/static/js/app.jsx
index f00618f..da87ae7 100644
--- a/app/static/js/app.jsx
+++ b/app/static/js/app.jsx
@@ -2165,7 +2165,7 @@ function fxRtStop(silent) {
 // ≈ 1792) + FILL buffer 16 block (4096) = 23 block ≈ 5888 (~123ms @48k). Giữ
 // đồng bộ với sf-fx-realtime.js. FX_RT_START_EST_MS: ước lượng khởi đầu khi
 // chưa có phép đo (fx_play_first) — dùng cho freeze playhead thay V39 0.31s.
-const FX_RT_ROUNDTRIP_SAMPLES = 5888;
+const FX_RT_ROUNDTRIP_SAMPLES = 7936;
 const FX_RT_START_EST_MS = 450;
 // G3: anchor processed — playhead = startOffset + (processed - anchor - latency)/sr
 // (da tru latency -> bam vi tri mau NGHE DUOC; pre-roll tu giu tai startOffset —
diff --git a/app/static/js/sf-fx-realtime.js b/app/static/js/sf-fx-realtime.js
index 000c115..c3fa205 100644
--- a/app/static/js/sf-fx-realtime.js
+++ b/app/static/js/sf-fx-realtime.js
@@ -29,8 +29,8 @@ class SfFxRealtimeProcessor extends AudioWorkletProcessor {
     super();
     this.BLOCK = 256;          // FXRT_BLOCK
     this.BURST = 4;            // số block gom 1 frame (bridge batch)
-    this.FILL = 16;             // V43: 16 block ~85ms @48k: buffer khởi đầu — hấp thụ jitter main-thread (GUI decode, rAF, VST panel). PDC 5888 = (7+16)*256 (fxRtApplyPdc). V40 giam 24->8 -> cushion = FILL - d ~3-8; pump/WS gap 42ms + queue 3 -> underrun (fx_stats u=1 q=0 trong log). V43 len 16 -> cushion ~11-16, ngang muc q=10-15 sau flush/resume (het underrun trong log).
-    this.RESUME_FILL = 16;     // V26: re-buffer khi resume SAU STOP (flush_for_stop) — 16 block ~85ms (V43: = FILL) → play kế tiếp bắt đầu nhanh; underrun-stall vẫn dùng FILL (crackle/wobble).
+    this.FILL = 24;             // V44: 24 block ~128ms @48k: buffer khởi đầu — hấp thụ jitter main-thread + stall deschedule bridge 68-138ms. PDC 7936 = (7+24)*256 (fxRtApplyPdc). V43 16 -> cushion ~9 (q 3-9) chua du: stall 68-82ms van gay underrun. V44 len 24 -> cushion ~17 (~90ms).
+    this.RESUME_FILL = 24;     // V26: re-buffer khi resume SAU STOP (flush_for_stop) — 16 block ~85ms (V43: = FILL) → play kế tiếp bắt đầu nhanh; underrun-stall vẫn dùng FILL (crackle/wobble).
     this.resumeFill = this.FILL; // mức re-buffer khi resume sau flush — stop: RESUME_FILL, underrun-stall: FILL
     this.CAP = 32;             // V40: cap queue chặn overflow (~170ms)
     this.HOLD_FADE = 4;        // 4 block ~21ms: fade 1→0 sau HOLD hết (hết click cắt cứng)
diff --git a/native_bridge/juce_fx/JuceFxLoop.cpp b/native_bridge/juce_fx/JuceFxLoop.cpp
index ada1265..c4048a7 100644
--- a/native_bridge/juce_fx/JuceFxLoop.cpp
+++ b/native_bridge/juce_fx/JuceFxLoop.cpp
@@ -121,7 +121,7 @@ int run_juce_fx_loop(const std::string& jobPath, const std::string& shmName,
 
 #ifdef _WIN32
     timeBeginPeriod(1);
-    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_ABOVE_NORMAL);
+    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST);
 #endif
 
     // Engine: prepare graph (chain theo fx_chain). sr/block từ job; header là
diff --git a/native_bridge/src/RealtimeFxLoop.cpp b/native_bridge/src/RealtimeFxLoop.cpp
index 2af7d64..46e59ff 100644
--- a/native_bridge/src/RealtimeFxLoop.cpp
+++ b/native_bridge/src/RealtimeFxLoop.cpp
@@ -141,7 +141,7 @@ int run_realtime_fx_loop(const std::string& jobPath, const std::string& shmName,
     // (fx-gui spawn + VST load instance thu 2, native VSTi GUI open...) preempt
     // -> underrun -> am bi "bop nghet"/ngat quan. ChannelWorker (main.cpp)
     // da dung THREAD_PRIORITY_ABOVE_NORMAL.
-    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_ABOVE_NORMAL);
+    SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_HIGHEST);
 #endif
     // Chờ chain ĐẦU TIÊN được worker build xong (gen>=1) trước khi READY.
     // setChain() là ASYNC — worker thread load VST3 + preset mất 1-4s; nếu set