glib critical when flipping modem hks on/off

Starting chatty with hks off, then flipping it on and off again gives:

(sm.puri.Chatty:3317): GLib-GObject-CRITICAL **: 11:28:34.864: g_object_unref: assertion 'G_IS_OBJECT (object)' failed

with the not very meaningful backtrace:

#0  0x0000ffff9b61d714 in raise () at /lib/aarch64-linux-gnu/libc.so.6
#1  0x0000ffff9c6d078c in g_logv () at /lib/aarch64-linux-gnu/libglib-2.0.so.0
#2  0x0000ffff9c6d0960 in g_log () at /lib/aarch64-linux-gnu/libglib-2.0.so.0
#3  0x0000ffff9c697cfc in  () at /lib/aarch64-linux-gnu/libglib-2.0.so.0
#4  0x0000ffff86647360 in  () at /usr/lib/purple-2/mm-sms.so
#5  0x0000ffff9c7bd9f8 in g_closure_invoke () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#6  0x0000ffff9c7d22b8 in  () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#7  0x0000ffff9c7da62c in g_signal_emit_valist () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#8  0x0000ffff9c7daffc in g_signal_emit_by_name () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#9  0x0000ffff9c938d80 in  () at /lib/aarch64-linux-gnu/libgio-2.0.so.0
#10 0x0000ffff9b488dcc in ffi_call_SYSV () at /lib/aarch64-linux-gnu/libffi.so.6
#11 0x0000ffff9b4896f4 in ffi_call () at /lib/aarch64-linux-gnu/libffi.so.6
#12 0x0000ffff9c7be338 in g_cclosure_marshal_generic () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#13 0x0000ffff9c7bd9f8 in g_closure_invoke () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#14 0x0000ffff9c7d22b8 in  () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#15 0x0000ffff9c7da62c in g_signal_emit_valist () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#16 0x0000ffff9c7dab98 in g_signal_emit () at /lib/aarch64-linux-gnu/libgobject-2.0.so.0
#17 0x0000ffff9c927a00 in  () at /lib/aarch64-linux-gnu/libgio-2.0.so.0
#18 0x0000ffff9c915658 in  () at /lib/aarch64-linux-gnu/libgio-2.0.so.0
#19 0x0000ffff9c6c951c in g_main_context_dispatch () at /lib/aarch64-linux-gnu/libglib-2.0.so.0
#20 0x0000ffff9c6c98e8 in  () at /lib/aarch64-linux-gnu/libglib-2.0.so.0
#21 0x0000ffff9c6c9984 in g_main_context_iteration () at /lib/aarch64-linux-gnu/libglib-2.0.so.0
#22 0x0000ffff9c8edc7c in g_application_run () at /lib/aarch64-linux-gnu/libgio-2.0.so.0
#23 0x0000aaaab904f504 in main (argc=1, argv=0xffffea4282d8) at ../src/main.c:28
        application = 0xaaaaf00a81a0