React App deployed on DigitalOcean has malformed urls at outgoing post requests to backend servers

I had well functioning http requests outgoing when i run my react app on localhost, but after I deployed it to Digital Ocean with: Build command: npm run build start command: npm start ( just as I was running it locally ) it started adding to the outgoing urls to the backend it’s own URL, meaning:

instead of (what should be the outgoing url): https://<backend-server-domain>/api/documentsign/ the url post-deployment became (malformed and doesnt work): https://<react-app-domain>/<backend-server-domain>/api/documentsign/

which is not something i configured on purpose at all, for sure not within the code… and this code worked for me in the past with previous deployments, im not sure what default configurations might have digital ocean changed to cause this…

I tried rebuilding the app multiple times without any luck, validated that with the same code, the running the app locally and at deployment does indeed have the above two different http port urls…

please help if you have an idea of what could have caused this.