Your web app is working on 80, but your router is 1880? - that port is not compatible with Cloudflare and Cloudflare cannot proxy traffic over it.
The same for 1443.
You should use one (or more) ports for your web app (at least on your router) which are compatible and on which Cloudflare can successfully connect.
Regarding the compatible ports with Cloudflare, kindly may I ask if you already have checked from the list below?:
You web app, the router should have ports compatible with Cloudflare, so Cloudflare could proxy your web app over them (the DNS records would be cloud, otherwise cloud).
There is an option to use Cloudflare Spectrum which is available on all paid plans.
But, Pro and Business plans support selected protocols only, whereas Enterprise supports all TCP and UDP based traffic.
More about it here: