Can't install or SSH tp-link C50

I have a tp-link archer c50 eu v3. Failed when flashing the standard firmware so used the 3rd party one linked from the tech page.

3rd party bin file uploads, but after it does I can't connect either through in a browser, or SSH in the terminal (mac). The internet works fine though. Using SSH I either get a port 22 connection refused error or a timeout. I've set sharing on in system prefs, as this seems to be how to open port 22 on mac, but it still doesn't work.

When I turn the router on and off it reverts to stock firmware and I have to start again from scratch.

Is there a way to fix this? I've tried reading all the guides but I'm completely new to openwrt so it's all a bit confusing. Thanks!

Which image did you use in the first place? openwrt-19.07.2-ramips-mt76x8-tplink_c50-v3-squashfs-tftp-recovery.bin ?