bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8) in singularity container

Question

Problem

I've had different .sif-files with various versions of ROS (ROS:kinetic and ROS:melodic is the ones I've used most). It worked flawlessly, until it suddenly started giving me this warning:

$ singularity shell ros-kinetic.sif 
bash: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8)
Singularity> 

I expected that singularity would give me the same state every time I ran the mentioned command? Am I using singularity incorrectly or is it something wrong with the image? Can it be a compatibility issue?

I figured it could be an issue with the images on https://hub.docker.com/r/osrf/ros, but they haven't updated their content in 7 months and the my setup work nicely (maximum) 2 months ago.

How I build the .sif files

$ singularity build --fakeroot ros-kinetic.sif docker://osrf/ros:kinetic-desktop-full

I've also tried using sudo instead of --fakroot option with the same result.

My system

$ cat /etc/os-release 
NAME="Red Hat Enterprise Linux"
VERSION="8.5 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.5"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.5 (Ootpa)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:8::baseos"
HOME_URL="https://www.redhat.com/"
DOCUMENTATION_URL="https://access.redhat.com/documentation/red_hat_enterprise_linux/8/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"

REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_BUGZILLA_PRODUCT_VERSION=8.5
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.5"
$ singularity --version
singularity version 3.8.5-2.el8

I've also tried with my Fedora 35 machine with the same result.