new vcore-3.1 500 do not extrude whit LGX and rapido phateus v2

Hello everyone, I'm encountering an issue with my RatRig V-Core 3.1 500mm. I've installed a new LGX extruder and a Phateus Rapido V2 hotend. Despite configuring everything correctly, the extruder clogs after about two layers and stops extruding. I've tried increasing the temperature to over 300 degrees, but the problem persists. the extruder try to extrude, but there is a block on the hotend... i've try to replace the hotend whit a newest but the problem persist...Has anyone experienced a similar issue or have any suggestions for other things I might try? Thank you in advance for your help!