WR841N v11 after flashing firmware for WR841N v9

Some time ago I flashed OpenWRT 15.05 for WR841N v9 onto my WR841N v11. At the time, it seemed to work fine, so I didn't worry much about it.

Recently, however I've been trying to replace 'OpenWRT 15.05' with an LEDE build. Specifically this one: Build for TP-Link TL-WR841N(D) [all versions]

If I try to upgrade through the web interface (luci), it gives me a mismatch error, so I have to use scp and ssh and perform 'sysupgrade -F firmware.bin'. This tells me that the upgrade was successful, but upon resetting (as well as hard resetting) the device, I always find myself back at 'OpenWRT 15.05 for WR841N v9'.

I've tried both 'lede-ar71xx-generic-tl-wr841-v11-squashfs-factory-us.bin' and 'lede-ar71xx-generic-tl-wr841-v11-squashfs-sysupgrade.bin' as well as the TP-Link factory images 'wr841nv9_wr841ndv9_en_3_16_9_up_boot(150310).bin' and 'wr841nv11_us_3_16_9_up_boot(151021).bin'. No matter what, after resetting the device, I end up with 'OpenWRT 15.05 for WR841N v9'.