diff --git a/source/brailleDisplayDrivers/brailliantB.py b/source/brailleDisplayDrivers/brailliantB.py
index 67670d80e9d..033ce1add0d 100644
--- a/source/brailleDisplayDrivers/brailliantB.py
+++ b/source/brailleDisplayDrivers/brailliantB.py
@@ -190,11 +190,27 @@ def __init__(self, port="auto"):
 
 	def _initAttempt(self):
 		if self.isHid:
+			# Ensure to set self.numCells only at the end of this method to prevent display writes before the capabilities/numCells request
+			numCells = 0
+			# First try to get cell count from _writeSize
+			try:
+				# _writeSize includes 4 bytes of overhead, so subtract 4
+				numCells = self._dev._writeSize - 4
+			except AttributeError:
+				log.debugWarning("Could not get _writeSize from HID device")
+
+			# Adjust numCells based on reported number of cells
 			try:
 				data: bytes = self._dev.getFeature(HR_CAPS)
+				reportedNumCells = data[24]
+				if reportedNumCells > 0:
+					# Update numCells based on reported cell count from the device
+					numCells = reportedNumCells
+				else:
+					log.debugWarning("Could not get number of cells from HID device using HR_CAPS")
 			except WindowsError:
 				return  # Fail!
-			self.numCells = data[24]
+			self.numCells = numCells
 		else:
 			# This will cause the display to return the number of cells.
 			# The _serOnReceive callback will see this and set self.numCells.
diff --git a/user_docs/en/changes.md b/user_docs/en/changes.md
index 0ebf692d4e0..b5239df173d 100644
--- a/user_docs/en/changes.md
+++ b/user_docs/en/changes.md
@@ -4,6 +4,8 @@
 
 ### Bug Fixes
 
+* Humanware Brailliant BI 40X devices running firmware version 2.4 now work as expected. (#17518, @bramd)
+
 ## 2024.4.1
 
 This is a patch release to fix a bug when saving speech symbol dictionaries.