Prevent TMUX exit on PTY OOM kill?

I have a high memory program (ML) that I want to run in a tmux session. However, if the process is OOM killed, the tmux session is also shut down. I partially solved it (using the below run-bg), but it still kills the tmux window it runs in (I suspect because of the PTY, but maybe not). How can I run this program, still have the stdin and stdout be from and to the tmux window, but not have tmux window exit when the program is OOM killed?

run-bg (what I actually use to run the high-memory process):

#!/bin/bash

unit="bg-$(date +%s%N)"

#get the environment args from the executing process
env_args=()

while IFS='=' read -r key val; do
    # Append each --setenv=KEY=VALUE (properly shell-escaped)
    env_args+=( "--setenv=${key}=$(printf '%q' "$val")" )
done < <(env)


# Start the command as a transient user service
systemd-run --user --pty \
    --unit="$unit" \
    --slice=runbg.slice \
    --property=MemoryMax=18G \
    --property=MemoryLimit=14G \
    --property=Delegate=yes \
    --working-directory="$PWD" \
    --expand-environment=yes \
    "${env_args[@]}" \
    "$@"

My tmux config:

set-option -g default-command 'bash -c run-bg-tmux'

run-bg-tmux (this allows for the tmux windows to be separate):

#!/bin/bash

unit="job-$(date +%s%N)"


systemd-run --user --scope \
    --slice=tmuxjobs.slice \
    --unit $unit \
    --property=MemoryMax=32G \
        --property=Delegate=yes \
    bash