first layer problems

Hello I have a ratrig v4 500. I haven’t managed the first layer of Perfect yet. The z offset is not right with every print and if I then set and save it correctly during the print and after the print then also save the config and restart, it is wrong again at the next print. I have already deactivated the beacon real z via contact. I have recalibrated the beacon several times. I performed an x axis twist compensation. The filament also led directly into the extruder without ptfe hose. All screws on the hotend checked again. And also all the other screws and connections, does anyone else have an idea?