There has been a lot of debate whether there is relativistic mass or not. Many textbooks used to include this concept but now even introductory university level textbooks like Halliday Resnick Krane Physics 5th edition, University Physics by Young and Freedman (13th edition onwards) don’t mention this mass variation concept. Even some qualified people have made videos on youtube to negate this concept completely.

https://arxiv.org/pdf/hep-ph/0602037.pdf
Even LHC people don’t buy this concept!
Why are you still using it?