Snipe-it and cloudflare tunnel issue

[creative0100]

I currently have 2 versions of Snipe-it running. first and original is a turnkey 6.x version that is currently accessible through CF to a domain name. I wanted to update this to v8.x of Snipe-it but never had any success with updating turnkey stuff. I want to move to the community version as the script update is perfect for what I want in the future

with the issues that I had with installing snipe-it, I got a version working. Set it up, Imported my backup file and on the local address, it works perfectly.

I have then updated the .env in the community scripted version with the same details as my original version ( APP_URL and TRUSTED_PROXIES, MAIL details ) and changed my CF tunnel to point to the new url but I get a 502 error when trying to access the domain. Switch CF back to the original url and it shows just fine. No other changes, just the url.

Very new to all this so I feel like I am missing something obvious... any pointers?