Considering oxidation mechanism of side-chains in arenes, it is known that side-chains get oxidized to carboxylic group ($-COOH$).
Below is a picture of 2-Methyl, 2-Phenyl Propane. When it gets refluxed with acidified $KMnO_4$ or acidified $K_2Cr_2O_7$, it should be oxidized to give benzoic acid.
But according to the provided source, it seems 2-Methyl, 2-Phenyl Propane doesn't react with the above oxidizing agents.
My question is,
Why does this compound disobey the general oxidation of benzyl derivatives?
Note, the source has a OH on position 4 of the ring, that makes it difficult for me to name it.
Source: https://papers.gceguide.com/A%20Levels/Chemistry%20(9701)/9701_s13_qp_41.pdf Qno:5 c) i)
Or is the OH that makes the difference in this question?