diff -ur harfbuzz.org/src/hb-graphite2.cc harfbuzz/src/hb-graphite2.cc
--- harfbuzz.org/src/hb-graphite2.cc	2023-07-08 12:33:00
+++ harfbuzz/src/hb-graphite2.cc	2023-07-08 12:37:46
@@ -363,9 +363,10 @@
       }
       else
       {
+	auto origin_X = gr_slot_origin_X (is) * xscale;
 	c->advance = 0;
-	clusters[ci].advance += gr_slot_origin_X(is) * xscale - curradv;
-	curradv += clusters[ci].advance;
+	clusters[ci].advance += origin_X - curradv;
+	curradv = origin_X;
       }
       ci++;
     }