Device(m2 ssd) remounts in readonly (sometimes with data corruption) mode only in battery mode

I have a brand new Dell Laptop with an Adata SSD. I've installed Ubuntu 18.04 and it seemed to work fine, but then I noticed that the root filesystem got corrupted more than once while in normal use.
Upon investigation, I've found that this seems to happen only when working on battery (that's why I took a while to notice the problem). When on AC, everything seems to be fine.

I've tried booting with a newer and an older kernel to see if the problem is solved. It looks like 4.15.0-72 has the same problem, while 5.4.2 (got this fromm mainline) works fine.

This is what appears on dmesg after unplugging AC while doing IO:

[ 9255.001789] ACPI Error: Thread 3916103680 cannot release Mutex [PATM] acquired by thread 130959116
8 (20181213/exmutex-382)
[ 9255.001796] No Local Variables are initialized for Method [_Q66]
[ 9255.001797] No Arguments are initialized for method [_Q66]
[ 9255.001798] ACPI Error: Method parse/execution failed \_SB.PCI0.LPCB.ECDV._Q66, AE_AML_NOT_OWNER (
20181213/psparse-531)
[ 9255.086788] EXT4-fs (sda2): re-mounted. Opts: errors=remount-ro,commit=600
[ 9269.895681] NMI watchdog: Enabled. Permanently consumes one hw-PMU counter.
[ 9270.201397] ata1: SATA link down (SStatus 4 SControl 300)
[ 9270.940318] EXT4-fs (sda2): re-mounted. Opts: errors=remount-ro,commit=0
[ 9331.341737] EXT4-fs (sda2): re-mounted. Opts: errors=remount-ro
[ 9345.125701] iwlwifi 0000:00:14.3: Invalid rate->type 0

HW Info

System: Host: vitor-note Kernel: 5.0.0-37-generic x86_64 bits: 64
           Desktop: Gnome 3.28.4 Distro: Ubuntu 18.04.3 LTS
Machine: Device: un-determined System: Dell product: Inspiron 5482 serial: N/A
           Mobo: Dell model: 0V8YD9 v: A02 serial: N/A
           UEFI: Dell v: 2.5.0 date: 07/29/2019
Battery BAT0: charge: 40.6 Wh 100.0% condition: 40.6/42.0 Wh (97%)
CPU: Quad core Intel Core i7-8565U (-MT-MCP-) cache: 8192 KB
           clock speeds: max: 4600 MHz 1: 740 MHz 2: 944 MHz 3: 955 MHz
           4: 1018 MHz 5: 1019 MHz 6: 959 MHz 7: 681 MHz 8: 1033 MHz
Graphics: Card-1: Intel Device 3ea0
           Card-2: NVIDIA GM108M [GeForce MX130]
           Display Server: x11 (X.Org 1.20.4 )
           drivers: modesetting,nvidia (unloaded: fbdev,vesa,nouveau)
           Resolution: 1920x1080@60.05hz
           OpenGL: renderer: GeForce MX130/PCIe/SSE2
           version: 4.6.0 NVIDIA 435.21
Audio: Card Intel Device 9dc8 driver: snd_hda_intel
           Sound: Advanced Linux Sound Architecture v: k5.0.0-37-generic
Network: Card: Intel Device 9df0 driver: iwlwifi
           IF: wlo1 state: up speed: N/A duplex: N/A mac: 04:ed:33:50:12:b6
Drives: HDD Total Size: 256.1GB (10.7% used)
           ID-1: /dev/sda model: ADATA_SU810NS38 size: 256.1GB
Partition: ID-1: / size: 234G used: 26G (12%) fs: ext4 dev: /dev/sda2
RAID: No RAID devices: /proc/mdstat, md_mod kernel module present
Sensors: System Temperatures: cpu: 60.0C mobo: N/A gpu: 48C
           Fan Speeds (in rpm): cpu: 3448
Info: Processes: 324 Uptime: 30 min Memory: 1595.7/7656.7MB
           Client: Shell (zsh) inxi: 2.3.56

Please let me know if you need any more information/testing

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-5.0.0-37-generic 5.0.0-37.40~18.04.1
ProcVersionSignature: Ubuntu 5.0.0-37.40~18.04.1-generic 5.0.21
Uname: Linux 5.0.0-37-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.9-0ubuntu7.9
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Thu Dec 5 13:05:09 2019
InstallationDate: Installed on 2019-11-28 (6 days ago)
InstallationMedia: Ubuntu 18.04.3 LTS "Bionic Beaver" - Release amd64 (20190805)
SourcePackage: linux-signed-hwe
UpgradeStatus: No upgrade log present (probably fresh install)