METAR Bug - TypeError on fetching not found METAR

[pdellaert]

{"context":"MetarService","stack":["TypeError: Cannot read property 'toUpperCase' of undefined\n    at MapSubscriber.project (/app/dist/metar/metar.service.js:98:62)\n    at MapSubscriber._next (/app/node_modules/rxjs/internal/operators/map.js:49:35)\n    at MapSubscriber.Subscriber.next (/app/node_modules/rxjs/internal/Subscriber.js:66:18)\n    at TapSubscriber._next (/app/node_modules/rxjs/internal/operators/tap.js:65:26)\n    at TapSubscriber.Subscriber.next (/app/node_modules/rxjs/internal/Subscriber.js:66:18)\n    at /app/node_modules/@nestjs/common/http/http.service.js:47:28\n    at processTicksAndRejections (internal/process/task_queues.js:85:5)"],"level":"error","message":"Cannot read property 'toUpperCase' of undefined"}

{"context":"MetarService","stack":["Error: METAR not available for ICAO: RJFU\n    at MetarService.generateNotAvailableException (/app/dist/metar/metar.service.js:105:27)\n    at CatchSubscriber.selector (/app/dist/metar/metar.service.js:101:24)\n    at CatchSubscriber.error (/app/node_modules/rxjs/internal/operators/catchError.js:46:31)\n    at MapSubscriber._next (/app/node_modules/rxjs/internal/operators/map.js:52:30)\n    at MapSubscriber.Subscriber.next (/app/node_modules/rxjs/internal/Subscriber.js:66:18)\n    at TapSubscriber._next (/app/node_modules/rxjs/internal/operators/tap.js:65:26)\n    at TapSubscriber.Subscriber.next (/app/node_modules/rxjs/internal/Subscriber.js:66:18)\n    at /app/node_modules/@nestjs/common/http/http.service.js:47:28\n    at processTicksAndRejections (internal/process/task_queues.js:85:5)"],"response":"METAR not available for ICAO: RJFU","status":404,"level":"error","message":"METAR not available for ICAO: RJFU" }

Will investigate.