(This is a guess because it’s really hard to obtain reliable information about De Lijn routes, especially this one operated by DL Limburg, for which many stops on their website do not exist at all.) The most logical situation is that buses are now leaving the fast lane onto the side road somewhere near the intersection with Avenue Lambeau/Lambeaulaan.  In that case, we should maybe create a small road connector there to re-route the bus relation.
According to aerial imagery, small road connectors across the intersection with Avenue Lambeau/Lambeaulaan are missing.  But I need your local knowledge about that, I haven’t been there since the works started.