diff --git a/common/jobs/jobs_output_archive.cpp b/common/jobs/jobs_output_archive.cpp
index 20d1a03d6f..b190235302 100644
--- a/common/jobs/jobs_output_archive.cpp
+++ b/common/jobs/jobs_output_archive.cpp
@@ -25,6 +25,7 @@
 #include <gestfich.h>
 #include <common.h>
 #include <wildcards_and_files_ext.h>
+#include <kiplatform/io.h>
 
 JOBS_OUTPUT_ARCHIVE::JOBS_OUTPUT_ARCHIVE() :
     JOBS_OUTPUT_HANDLER(),
@@ -61,14 +62,17 @@ bool JOBS_OUTPUT_ARCHIVE::HandleOutputs( const wxString&                baseTemp
 
     wxFFileOutputStream ostream( outputPath );
 
-    if( !ostream.IsOk() ) // issue to create the file. Perhaps not writable dir
+    if( !ostream.IsOk() )
     {
-        //msg.Printf( _( "Failed to create file '%s'." ), aDestFile );
-        //aReporter.Report( msg, RPT_SEVERITY_ERROR );
         aResolvedOutputPath.reset();
         return false;
     }
 
+    // Use a large I/O buffer to improve compatibility with cloud-synced folders.
+    // See KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE comment for details.
+    if( FILE* fp = ostream.GetFile()->fp() )
+        setvbuf( fp, nullptr, _IOFBF, KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE );
+
     wxZipOutputStream zipstream( ostream, -1, wxConvUTF8 );
     wxString          errors;
 
diff --git a/common/project/project_archiver.cpp b/common/project/project_archiver.cpp
index 60ec69134c..bf3fb44284 100644
--- a/common/project/project_archiver.cpp
+++ b/common/project/project_archiver.cpp
@@ -252,6 +252,10 @@ bool PROJECT_ARCHIVER::Archive( const wxString& aSrcDir, const wxString& aDestFi
         return false;
     }
 
+    // Use a large I/O buffer to improve compatibility with cloud-synced folders.
+    if( FILE* fp = ostream.GetFile()->fp() )
+        setvbuf( fp, nullptr, _IOFBF, KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE );
+
     wxZipOutputStream zipstream( ostream, -1, wxConvUTF8 );
 
     wxDir projectDir( aSrcDir );
diff --git a/libs/kiplatform/include/kiplatform/io.h b/libs/kiplatform/include/kiplatform/io.h
index cfd17194a2..357ff6d839 100644
--- a/libs/kiplatform/include/kiplatform/io.h
+++ b/libs/kiplatform/include/kiplatform/io.h
@@ -21,6 +21,7 @@
 #define KIPLATFORM_IO_H_
 
 #include <stdio.h>
+#include <cstddef>
 
 class wxString;
 class wxFileName;
@@ -29,6 +30,15 @@ namespace KIPLATFORM
 {
 namespace IO
 {
+    /**
+     * Buffer size for file I/O operations on cloud-synced folders.
+     *
+     * Cloud sync services like Google Drive, OneDrive, and Dropbox can report stale file sizes
+     * during seek operations immediately after writing. Using a 512KB buffer reduces the number
+     * of I/O operations and allows the cloud sync driver to flush data more reliably before
+     * subsequent reads. This value was determined empirically to eliminate sync issues.
+     */
+    static constexpr size_t CLOUD_SYNC_BUFFER_SIZE = 512 * 1024;
     /**
      * Opens the file like fopen but sets flags (if available) for sequential read hinting.
      * Only use this variant of fopen if the file is truely going to be read sequentially only
diff --git a/pcbnew/dialogs/dialog_export_odbpp.cpp b/pcbnew/dialogs/dialog_export_odbpp.cpp
index 558bc33733..87114ee03e 100644
--- a/pcbnew/dialogs/dialog_export_odbpp.cpp
+++ b/pcbnew/dialogs/dialog_export_odbpp.cpp
@@ -49,6 +49,7 @@
 #include <io/io_mgr.h>
 #include <jobs/job_export_pcb_odb.h>
 #include <pcb_io/pcb_io_mgr.h>
+#include <kiplatform/io.h>
 
 
 
@@ -462,6 +463,12 @@ void DIALOG_EXPORT_ODBPP::GenerateODBPPFiles( const JOB_EXPORT_PCB_ODB& aJob, BO
             aProgressReporter->AdvancePhase( _( "Compressing output" ) );
 
         wxFFileOutputStream fnout( outputFn.GetFullPath() );
+
+        // Use a large I/O buffer to improve compatibility with cloud-synced folders.
+        // See KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE comment for details.
+        if( FILE* fp = fnout.GetFile()->fp() )
+            setvbuf( fp, nullptr, _IOFBF, KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE );
+
         wxZipOutputStream   zipStream( fnout );
 
         std::function<void( const wxString&, const wxString& )> addDirToZip =
@@ -505,6 +512,12 @@ void DIALOG_EXPORT_ODBPP::GenerateODBPPFiles( const JOB_EXPORT_PCB_ODB& aJob, BO
     else if( aJob.m_compressionMode == JOB_EXPORT_PCB_ODB::ODB_COMPRESSION::TGZ )
     {
         wxFFileOutputStream fnout( outputFn.GetFullPath() );
+
+        // Use a large I/O buffer to improve compatibility with cloud-synced folders.
+        // See KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE comment for details.
+        if( FILE* fp = fnout.GetFile()->fp() )
+            setvbuf( fp, nullptr, _IOFBF, KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE );
+
         wxZlibOutputStream  zlibStream( fnout, -1, wxZLIB_GZIP );
         wxTarOutputStream   tarStream( zlibStream );
 
diff --git a/pcbnew/pcbnew_jobs_handler.cpp b/pcbnew/pcbnew_jobs_handler.cpp
index 800374d32b..19e8f79d84 100644
--- a/pcbnew/pcbnew_jobs_handler.cpp
+++ b/pcbnew/pcbnew_jobs_handler.cpp
@@ -89,6 +89,7 @@
 #include <wx/wfstream.h>
 #include <wx/zipstrm.h>
 #include <wx/filename.h>
+#include <kiplatform/io.h>
 #include <settings/settings_manager.h>
 #include <dialogs/dialog_gendrill.h>
 #include <dialogs/dialog_gen_footprint_position.h>
@@ -2509,6 +2510,12 @@ int PCBNEW_JOBS_HANDLER::JobExportIpc2581( JOB* aJob )
 
         {
             wxFFileOutputStream fnout( zipfn.GetFullPath() );
+
+            // Use a large I/O buffer to improve compatibility with cloud-synced folders.
+            // See KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE comment for details.
+            if( FILE* fp = fnout.GetFile()->fp() )
+                setvbuf( fp, nullptr, _IOFBF, KIPLATFORM::IO::CLOUD_SYNC_BUFFER_SIZE );
+
             wxZipOutputStream   zip( fnout );
             wxFFileInputStream  fnin( tempFile );