App access via Cloudflare tunnel

I have just spun up vikunja in docker. I can access it fine from the browser interface via both internal and external networks by using a cloudflare tunnel.

I am unable to use the android app except via internal network. Using the cloudflare tunnel causes an error, screenshot below.

Anyone tried using the app via a cloudflare tunnel before?

Maybe this is caused by some kind of cloudflare captcha?

Possibly? Would be the first one I run into for my personal stuff.

It’s purely when data is going via the tunnel. VPN or directly on internal network no worries at all.

I think I read something about SSL causing issues with the app? (might have been something else and I am getting muddled). Cloudflare is doing its normal middle man stuff.

I have turned off the RUM features which were injecting some js for tracking by default, page source looks identical whether using the tunnel or not as far as a browser goes.

Not sure how the app works? Does it just wrap the website or makes calls more directly to the API?

Edit: for my uses it all works, my VPN auto connects and its all “wife approved” but interested in trying to work out what is going on to improve the knowledge base.