bug in ghci module loading post 9.12.4?

I recently upgraded from ghc 9.2 to 9.6 (I know, I'm slow), and one of
the things I was looking forward to was better recompilation
avoidance, that wouldn't be fooled by spurious mtime changes that are
common with with e.g. git branch switches.  Unfortunately, it seems to
have gotten buggy at the same time!  I upgraded again to 9.12.4 and it
looks like it's still buggy.  Either that or I'm doing things wrong
somehow.  Here's a repro, it requires 3 modules:

% cat >BugA.hs
module BugA where

x :: Int
x = 13
% cat >BugB.hs
module BugB where
import qualified BugA

f :: IO ()
f = print BugA.x
% cat >BugC.hs
module BugC where
import qualified BugB

bug :: IO ()
bug = BugB.f

% ghci -fobject-code # compile so we can load .o
GHCi, version 9.12.4: https://www.haskell.org/ghc/  :? for help
Loaded GHCi configuration from /Users/elaforge/qlib/dotfiles/.ghci
Prelude> :load BugC
[1 of 3] Compiling BugA             ( BugA.hs, BugA.o )
[2 of 3] Compiling BugB             ( BugB.hs, BugB.o )
[3 of 3] Compiling BugC             ( BugC.hs, BugC.o )
Ok, three modules loaded.
Leaving GHCi.
% ghci
Prelude> :load BugC
Ok, three modules loaded.
Prelude BugC> bug
13

As expected!  Now go edit BugA.hs, and change 13 to say 14, and save.
Now reload:

Prelude BugC> :r
[1 of 3] Compiling BugA             ( BugA.hs, interpreted ) [Source
file changed]
Ok, three modules reloaded.
Prelude BugC> bug
13

So that's not right!  This will also cause linking errors if something
was removed, though it's easier to reproduce the stale values.

For my interpretation of what's going on, I believe previously it
would have also reloaded BugB.  While it has noticed that BugA must be
reloaded (and switched to bytecode), it hasn't noticed that BugB is in
the dependency path and should also be reloaded, and possibly winds up
using stale values inlined into BugB.o.

Is it a bug?
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