When I got the RIsing tide quest, i was part of a moutain clan but since i got kicked before my railjack was completed, I relied on using other clan dojos to build my railjack due to my drydock at my newly made clan was still in need of tellerium. Then came the day I completed it, the railjack was visible in my orbiter but then I could not enter my railjack though the back of the orbiter.