After reinstalling firmware, always boots in Luci

I am using the Beryl MT1300.

I previously installed plain openWRT on my router and am looking to revert. I have attempted to reset in multiple ways:

When this completes, the router has the SSID GL-MT1300-889-5G (note the 889) and although the router is ostensibly reset (there's no root password for example, and the SSID reverts if I change it), the router is stuck in Luci. When the SSID comes up and I connect to it, navigating to 192.168.8.1 immediately redirects to Luci and I am able to log in with no password.

How can I ensure this install fully resets, so that I can use the GL-INET web UI?

I am attempting to install 4.3.19 and have also tried 4.3.18. Just pasting an example to confirm I am not installing upstream openWRT
https://fw.gl-inet.com/firmware/mt1300/release4/openwrt-mt1300-4.3.19-0823-1724384445.bin

Mostly browser caching. Try a different browser / incognito mode.

This was it, thank you very much!