ConnectCore 8M Mini: DNS not working with wired Ethernet but does with WiFi

I’m building an image for the ConnectCore 8M Mini using dey-4.0. It’s dey-image-lvgl with a few more applications added in; no new networking-related applications and no changes to NetworkManager’s configuration. The wired Ethernet connection is set up for DHCP and it acquires an IP address without issue. However, my device doesn’t configure a list of DNS servers from the local DHCP server. If I use the Wi-Fi connection, DNS works just fine. I’ve confirmed this behavior on multiple networks on which DNS works fine for the wired Ethernet on my laptop.

Here is the contents of /etc/NetworkManager/NetworkManager.conf:

[main]
plugins=ifupdown,keyfile
no-auto-default=type:ethernet
dns=dnsmasq
rc-manager=file

[ifupdown]
managed=false

[keyfile]
unmanaged-devices=interface-name:p2p*;interface-name:wlan1

[device]
wifi.scan-rand-mac-address=no

[digi-recovery]
ifdownup=false

Here is the contents of /etc/nsswitch.conf:

# /etc/nsswitch.conf
#
# Example configuration of GNU Name Service Switch functionality.
# If you have the `glibc-doc' and `info' packages installed, try:
# `info libc "Name Service Switch"' for information about this file.

passwd:         compat
group:          compat
shadow:         compat

hosts:          files myhostname  dns
networks:       files

protocols:      db files
services:       db files
ethers:         db files
rpc:            db files

netgroup:       nis

I don’t notice anything that would trigger a difference between wired Ethernet and Wi-Fi DNS operation. Anyone know of a reason why I would be seeing this problem and how to fix it?