We've a Craft 3 site hosted with Digital Ocean (Serverpilot set-up) with the DNS routed through Cloudflare.
The client has experienced issues uploading large ZIP files to (c140MB), returning a 413 error. After updating the PHP conf to enable larger files and tweaked the Nginx conf realised that the issue was with Cloudflare file upload limit.
Having set up a subdomain for the site to bypass Cloudflare we are now getting 500 errors in the browser console when trying to upload large files through the Craft control panel:
POST https://admin.site.com/index.php?p=admin/actions/assets/save-asset 500
There are no errors in the server logs and nothing showing up in the Craft debug toolbar.
Any suggestions on debugging and resolving this issue or on what might be causing the 500 error?