That is probably because you need to “commit” these settings via luci, otherwise any reboot of a device will clean that settings up. Nevertheless, I am using another solution, suggested in neighbor thread: it persistent at router’s memory after reboots, launches fan dynamically, adjusts entire system temperature to desired level on the one hand, and not forcing fan to work at max speed all the time, which increase its life a bit on the other. I am using it at my router with active Wireguard client, Synology NAS and about 5-6 devices connected via Wi-Fi, the average temperature of router ~52C which is quite good.
I wrote to support team that suggested threshold at 85C is much more than technical T ranges for motherboard used at AXT1800, so lets see how they handle it. Until that, you can resolve it with commands:
/etc/init.d/gl_fan stop
uci set glfan.@globals[0].temperature='60'
uci set glfan.@globals[0].integration='4'
uci set glfan.@globals[0].differential='20'
uci commit glfan
/etc/init.d/gl_fan restart