Hi, I tried but cannot reproduce this. Could you please try running the script below and pasting the full output here? Everywhere I have tested it, it works.
#!/bin/bash
cd /tmp && mkdir root-tbb-test && cd root-tbb-test
git clone https://github.com/root-project/root
mkdir build && cd build
cmake ../root -Dbuiltin_tbb=ON
cmake --build . --target TBB