TP-Link TL-WA854RE incorrectly assigns gateway (192.168.0.254 instead of 192.168.0.1) and now no IPv4 at all.

Description:
I’m having a repeated issue with my TP-Link TL-WA854RE range extender related to the default gateway and IPv4 configuration.

1. Initial problem: Wrong gateway assigned by the extender

When connecting to my extended network (SSID_EXT), my computer received:

• IPv4 address: 192.168.0.xxx

• But the gateway was 192.168.0.254 — the IP of the extender itself, not my router (192.168.0.1).

As a result, there was no internet access, because the extender was not passing the correct default gateway from the router.

2. Attempt to fix by assigning LAN settings manually

I tried to manually configure LAN settings on the extender:

• IP: 192.168.0.254

• Mask: 255.255.255.0

• Gateway: 192.168.0.1

• DHCP: Disabled

After doing this, the situation became worse:
The extender completely stopped providing any IPv4 addresses to clients.
When connected to EXT, ipconfig showed only IPv6, with no IPv4 address or IPv4 gateway at all.

3. Full factory reset and repeated setup

I performed a full 10–12 second factory reset, reconfigured the device from scratch (Quick Setup, no manual settings, no WPS), but the problem returned immediately:

• EXT again gives the wrong gateway (192.168.0.254) instead of my router’s gateway (192.168.0.1).

• And after a few attempts, IPv4 again stops being assigned entirely.

Current situation:

• All LEDs are solid (Power, Wi-Fi signal, RE).

• The extender panel at 192.168.0.254 opens normally.

• The extender reports that it is connected to the main router.

• But when I connect to EXT, I either receive:

  • wrong gateway 192.168.0.254, or

  • no IPv4 at all (only IPv6).

What I need help with:

Has anyone seen this behavior before?
Why does TL-WA854RE keep assigning itself as the default gateway instead of relaying the router’s gateway?
Why does IPv4 stop working entirely after the extender attempts to “fix” its gateway?

Is this a firmware bug, a compatibility issue with certain routers, or a known DHCP forwarding failure on this model?

Any guidance would be appreciated.