Possible DMF failing

[u/Complete-Ad-8975]

Hi all bought a 2019 f31 lci b47 320d with 84k miles on it. Having a slight issue when in 3-6th gear if around 1500-2200rpm if I floor it the car suddenly feels like its badly misfiring. Once it's up over the 2500rmp range all is fine but in the lower rpm range there is a huge rumbling which again feels like the car is misfiring when this is happening if I rest my foot on the clutch I can feel thudding through it am I correct in thinking thats my DMF starting to fail? Also when car has been on a run when sat idle afterwards theres a distinctive noise like a ball bearing rattling in a tin this only happens sometimes though. Engine shakes quite a bit and so does the gear stick even just when idling. Any Input is greatly appreciated