I’d recommend reviewing this page in the FBW docs: Discontinuities - FlyByWire Simulations Documentation
Discontinuities are a normal part of the flight plan not just for Airbus but also Boeing and other aircraft. If you’re not vectoring yourself and are not being vectored by ATC (e.g. Vatsim) you can just delete the discontinuity using the CLR key, which will directly connect the two waypoints together and the aircraft will follow the plan on NAV mode just fine. Just take care on some SIDs and STARs where direct-to is not really expected and there’s a good amount of vectoring that would usually occur (could be sharp angles, terrain, etc.). Usually you’re fine to delete it though.