diff --git a/src/device/usbd.h b/src/device/usbd.h
index 3ab6c813f..cf500143a 100644
--- a/src/device/usbd.h
+++ b/src/device/usbd.h
@@ -421,7 +421,7 @@ TU_ATTR_WEAK bool tud_vendor_control_xfer_cb(uint8_t rhport, uint8_t stage, tusb
 /* Standard AS Isochronous Feedback Endpoint Descriptor(4.10.2.1) */
 #define TUD_AUDIO_DESC_STD_AS_ISO_FB_EP_LEN 7
 #define TUD_AUDIO_DESC_STD_AS_ISO_FB_EP(_ep, _interval) \
-  TUD_AUDIO_DESC_STD_AS_ISO_FB_EP_LEN, TUSB_DESC_ENDPOINT, _ep, (uint8_t) (TUSB_XFER_ISOCHRONOUS | TUSB_ISO_EP_ATT_NO_SYNC | TUSB_ISO_EP_ATT_EXPLICIT_FB), U16_TO_U8S_LE(4), _interval
+  TUD_AUDIO_DESC_STD_AS_ISO_FB_EP_LEN, TUSB_DESC_ENDPOINT, _ep, (uint8_t) ((uint8_t)TUSB_XFER_ISOCHRONOUS | (uint8_t)TUSB_ISO_EP_ATT_NO_SYNC | (uint8_t)TUSB_ISO_EP_ATT_EXPLICIT_FB), U16_TO_U8S_LE(4), _interval
 
 // AUDIO simple descriptor (UAC2) for 1 microphone input
 // - 1 Input Terminal, 1 Feature Unit (Mute and Volume Control), 1 Output Terminal, 1 Clock Source
diff --git a/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h b/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h
index 3f4db985d..ade64b4fb 100644
--- a/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h
+++ b/src/portable/st/stm32_fsdev/dcd_stm32_fsdev_pvt_st.h
@@ -296,6 +296,16 @@ TU_ATTR_ALWAYS_INLINE static inline uint32_t pcd_get_ep_rx_cnt(USB_TypeDef * USB
 {
 #ifdef FSDEV_BUS_32BIT
   (void) USBx;
+  /* WA: few cycles for RX PMA descriptor to update, otherwise doesn't return the correct value.
+     Note: required for G0, U5, H5 etc.
+  This workaround is ported from stm32h5xx_hal_pcd.h and fixes the issue when calling this function fast enough.
+  Reproduced with GCC ast optimization(O2/O3) and stm32h573i_dk with an high frequency.
+  Observed on Windows 10 where tud_task() is scheduled by interrupt handler.
+  */
+  volatile uint32_t count = 10; // defined as PCD_RX_PMA_CNT in stm32 hal_driver
+  while (count > 0U) {
+    count--;
+  }
   return (pma32[2*bEpIdx + 1] & 0x03FF0000) >> 16;
 #else
   __I uint16_t *regPtr = pcd_ep_rx_cnt_ptr(USBx, bEpIdx);