Try removing the root path directive...

server/Dockerfile

@@ -15,4 +15,4 @@ ENV DB_LOCATION="/app/vacation.db"
 
 COPY app.py .
 
-CMD uvicorn app:app --host 0.0.0.0 --port 5000 --root-path /vacation-planner/api
+CMD uvicorn app:app --host 0.0.0.0 --port 5000