https://bugs.gentoo.org/878099
https://github.com/transmission/transmission/issues/3150

--- a/qt/FileTreeDelegate.cc
+++ a/qt/FileTreeDelegate.cc
@@ -49,7 +49,7 @@
     if (column == FileTreeModel::COL_PROGRESS)
     {
         QStyleOptionProgressBar p;
-        p.state = option.state | QStyle::State_Small;
+        p.state = option.state | QStyle::State_Horizontal | QStyle::State_Small;
         p.direction = qApp->layoutDirection();
         p.rect = option.rect;
         p.rect.setSize(QSize(option.rect.width() - 4, option.rect.height() - 8));
--- a/qt/TorrentDelegate.cc
+++ a/qt/TorrentDelegate.cc
@@ -545,7 +545,7 @@
         progressBarState = QStyle::State_None;
     }
 
-    progressBarState |= QStyle::State_Small;
+    progressBarState |= QStyle::State_Horizontal | QStyle::State_Small;
 
     QIcon::Mode const emblemIm = isItemSelected ? QIcon::Selected : QIcon::Normal;
     QIcon const emblemIcon = tor.hasError() ? getWarningEmblem() : QIcon();
--- a/qt/TorrentDelegateMin.cc
+++ a/qt/TorrentDelegateMin.cc
@@ -218,7 +218,7 @@
         progressBarState = QStyle::State_None;
     }
 
-    progressBarState |= QStyle::State_Small;
+    progressBarState |= QStyle::State_Horizontal | QStyle::State_Small;
 
     QIcon::Mode const emblemIm = isItemSelected ? QIcon::Selected : QIcon::Normal;
     QIcon const emblemIcon = tor.hasError() ? getWarningEmblem() : QIcon();