docker exec as user not working with sysbox-runc on Ubuntu 23.04 (Lunar)

I've hit an issue where I'm unable to run docker exec --user for sysbox-runc containers on Ubuntu 23.04. For any user which doesn't exist in the image (but does in the container) I get the following error:

unable to find user [...]: no matching entries in passwd file

The same issue doesn't happen when using the default (runc) container runtime.

My best (semi-informed) guess is that it's somehow looking at the wrong filesystem layer and only seeing the /etc/passwd from the image.

I've written a script to reproduce the error but the manual steps are:

docker run --runtime=sysbox-runc --detach --rm --name "jammy" -t "ubuntu:jammy"
docker exec -ti "jammy" useradd execuser
docker exec -ti "jammy" cat /etc/passwd
docker exec --user "execuser" -ti "jammy" id
docker stop jammy

Environment
lsb_release:

No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 23.04
Release:	23.04
Codename:	lunar

uname:

Linux lunar-amd64 6.2.0-20-generic #20-Ubuntu SMP PREEMPT_DYNAMIC Thu Apr  6 07:48:48 UTC 2023 x86_64 x86_64 x86_64 GNU/Linux

docker:

Docker version 23.0.6, build ef23cbc

sysbox:

sysbox-mgr
	edition: 	Community Edition (CE)
	version: 	0.6.1
	commit: 	ba99c0e7088f1e1ab51f95551f50de9524176655
	built at: 	Sat Apr  8 06:08:57 UTC 2023
	built by: 	Rodny Molina