cvsweb diff is always from most recent commit

Hello,

I'm investigating enabling Dolby Atmos for a X1 Carbon 10 and reviewing 
src/sys/dev/pci/azalia_code.c on cvsweb. My laptop has an ALC287 so I started 
reviewing changes with revision 1.183.

When I click the diff link on revision 1.183 I get a diff between 1.182 
(previous as expected) and the current revision. I expected a diff between 
1.182 and 1.83, not between 1.182 and 1.189.

Checking other file's diff links produces the same result, a diff between 
previous and the most recent commit. If I request a diff via cvs on the 
command line between specific revisions it works as I expect. Do I 
misunderstand how cvsweb works? I vaguely recall it was the expected diff 
before the most recent rewrite.

Here is the preamble when I click the diff link on revision 1.182.

Index: src/sys/dev/pci/azalia_codec.c
diff -u src/sys/dev/pci/azalia_codec.c:1.182 src/sys/dev/pci/azalia_codec.c:1.189
--- src/sys/dev/pci/azalia_codec.c:1.182	Sat Oct 24 22:54:38 2020
+++ src/sys/dev/pci/azalia_codec.c	Wed Sep  7 21:35:39 2022
@@ -1,4 +1,4 @@
-/*	$OpenBSD: azalia_codec.c,v 1.182 2020/10/25 02:54:38 jsg Exp $	*/
+/*	$OpenBSD: azalia_codec.c,v 1.189 2022/09/08 01:35:39 jsg Exp $	*/
 /*	$NetBSD: azalia_codec.c,v 1.8 2006/05/10 11:17:27 kent Exp $	*/


James