Entware Unsuccessful Entware installation on Asus RX-AX68U with Asuswrt-Merlin 3004.388.11

[jt99999]

I flashed my Asus RT-AX68U to AsusWRT-Merlin 3004.388.11 a couple days ago. Everything seems working fine afterwards.
I then tried amtm Entware on an ext4 USB drive.
The installation went fine but it ended without any indication such as successful or failure.
The last few lines shown in the terminal:
...
Downloading https://bin.entware.net/aarch64-k3.10/entware-upgrade_1.0-1_all.ipk
Configuring libgcc.
Configuring libc.
Configuring libssp.
Configuring libpthread.
Configuring librt.
Configuring terminfo.
Configuring libpcre2.
Configuring grep.
Configuring locales.
Entware uses separate locale-archive file independent from main system
Creating locale archive /opt/usr/lib/locale/locale-archive
Adding en_EN.UTF-8

And then the router rebooted a few moments later.

Below are some more findings...
# ls /opt
ls: /opt: No such file or directory
# cat /jffs/scripts/post-mount
#!/bin/sh

# grep amtm /tmp/syslog.log
Feb 22 08:17:56 amtm disk check: Probing 'ext4' on device /dev/sda1
Feb 22 08:17:56 amtm disk check: Running disk check with command 'e2fsck -p' on /dev/sda1
Feb 22 08:18:00 amtm disk check: Disk check done on /dev/sda1

I'd appreciate any help in getting Entware installed successfully before installing Tailmon 1.3.0.

Thank you!

 

[Ripshod]

You using an sd card or ssd?

 

[jt99999]

You using an sd card or ssd?

an USB stick formatted to Ext4.

 

[Ripshod]

an USB stick formatted to Ext4.

I'm not saying this with 100% certainty but your usb stick may be failing. Happens with excessive writes to the memory on it. Do you have another to test with?
As always I'd recommend an ssd anyway.